System for evulsing subcutaneous tissue

ABSTRACT

A system for evulsing subcutaneous tissue includes an endoscope adapted to be inserted into subcutaneous tissue through a skin cut portion to observe tissue to be evulsed and existing under the skin, a dissecting unit adapted to be inserted into the subcutaneous tissue through the skin cut portion so as to dissect the tissue, to be evulsed, from surrounding tissue in order to form a cavity along the tissue to be evulsed and below the skin, a cavity maintaining unit adapted to be inserted from the skin cut portion into the cavity formed by the dissecting unit and to be retained in the cavity in order to maintain, around the tissue to be evulsed, a treatment space which permits the endoscope to be inserted and removed and which enables treatment of the tissue to be evulsed, and at least one treatment tool adapted to be inserted into the treatment space maintained by the cavity maintaining unit in order to perform, in the treatment space, treatment required to evulse the tissue to be evulsed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for evulsing subcutaneoustissue represented by a subcutaneous blood vessel, such as a saphenousvein, by using an endoscope.

2. Description of the Related Art

When, for example, an operation for bypassing a blood vessel in theheart is performed, a saphenous vein existing in the leg of the body isextracted in order to use the saphenous vein as a bypass blood vessel.When the saphenous vein is extracted, an operation for separating thesaphenous vein from other textures is initially required. The uppertexture of the saphenous vein has a structure formed by sequentiallystacking the connective tissue covering the saphenous vein, and fat andthe skin formed on the connective tissue.

When an operation for extracting the subcutaneous blood vessel, such asthe saphenous vein in the lower extremity, is performed, the skin isincised along the blood vessel below the skin with, for example, aknife. Then, the subcutaneous tissue, such as the panniculus adiposis,in the lower layer of the skin and the connective tissue on the bloodvessel are incised so that the blood vessel having a length intended tobe extracted is exposed. The two ends of the exposed blood vessel arecut and taken out to the outside of the body. However, the extractingoperation results in the skin being considerably incised, and anexcessively long time is required to be cured for the patient to becured. What is worse, the incised portion is scarred and hardened, thuscausing a problem to in that the patient has a cramp in the leg when hemoves the leg and thus the patient feels a pain.

Accordingly, it might be considered feasible to extract the subcutaneousblood vessel, such as the saphenous vein, through a small cut portion onthe skin in the lower extremity. The other methods for extracting thesubcutaneous blood vessel, such as the saphenous vein, through a smallcut portion of the skin have been disclosed in, for example, U.S. Pat.No. 4,793,346 and U.S. Pat. No. 5,373,840. Especially, the methoddisclosed in U.S. Pat. No. 5,373,840 is concerned with extracting thesubcutaneous blood vessel by using an endoscope.

The method disclosed in U.S. Pat. No. 4,793,346 has the steps ofincising the skin of the lower extremity; inserting, through the incisedportion, a tube having an inner diameter somewhat larger than the outerdiameter of the vein; and allowing an electric current to flow through aknife disposed at the leading end of the tube, so that the tube is movedforwards while being rotated. As a result, the side branches of the veinare cauterized and cut by the knife so that the vein is extracted.

The method disclosed in U.S. Pat. No. 5,373,840 is arranged to use anendoscope having a channel extending longitudinally to take out an endof the blood vessel, to be extracted, through a cut portion of the bodyof a patient. Thus, the blood vessel is held by a grip means through thechannel of the endoscope and the blood vessel is removed by cutting.

However, the method disclosed in U.S. Pat. No. 4,793,346 is a method ofblindly moving forwards the tube having the knife. Therefore, theforegoing method has a risk of the saphenous vein, intended to beextracted, being undesirably cut in addition to the fact that thesaphenous vein is not straight in general. Moreover, the method has arisk of the saphenous vein being burnt thermally due to the electriccurrent allowed to flow from the knife.

With the method disclosed in U.S. Pat. No. 5,373,840, the endoscope ismoved forward along the blood vessel and any one of a variety oftreatment tools is inserted into the body through the channel of theendoscope. Then, the tissue is ablated by the treatment tool while beingobserved through the endoscope so that the blood vessel is treated.Therefore, a too complicated operation is required and a long time isrequired to complete the operation. What is worse, if the objective lensof the endoscope is contaminated with blood or the like, a complicatedoperation is required in which all of the devices are removed to theoutside of the body.

In a case where the skin is cut to permit the endoscope and thetreatment tool to be inserted into the lower extremity through the cutportion so as to extract the subcutaneous blood vessel, a cavity isrequired around the subcutaneous blood vessel because the blood vesselexists under the skin in which no cavity exists. That is, the bloodvessel and the other portions including the connective tissue arerequired to be considerably apart from each other so as to form aworking space between the blood vessel and the connective tissue toextract the blood vessel. However, a cavity cannot easily be formedaround the subcutaneous blood vessel because the subcutaneous tissue,such as the panniculus adiposis, and the connective tissue on the bloodvessel exist around the subcutaneous blood vessel.

A cannula for forming a cavity, into which the endoscope and thetreatment tool can be inserted, in the body and which permits treatmentand observation of a diseased part to be performed in the cavity withthe endoscope has been disclosed in, for example, WO93/10704. Thecannula has a body formed into a cylindrical shape having two openedends. Moreover, a slit is formed along the axis of the cylindrical bodyof the cannula. The cannula is used such that the leading end of thebody of the cannula is introduced into the body through an incisedportion of the skin, and then its leading end is discharged to theoutside of the body through another incised portion so that the two endopenings are exposed and thus a cavity is formed in the body cavity.After the cavity has been formed in the body cavity by the cannula, theendoscope is introduced into the cannula through one of the openings ofthe body of the cannula, that is, into the cavity formed by the cannula.Moreover, a treatment tool is, through another opening or the slit ofthe body of the cannula, introduced into the cavity formed by thecannula. Thus, while observing the diseased part through the endoscope,the diseased part can be treated by the treatment tool.

Although the cannula is suitable to be in an operation for ablating adiseased part in the fibrous tissue as is performed in surgicaltreatment of a carpal tunnel syndrome, the cannula is unsuitable to bein an operation for extracting the subcutaneous blood vessel, such asthe saphenous vein in the lower extremity, because a satisfactorilylarge cavity cannot be formed. If a satisfactorily large cavity cannotbe formed, the endoscope and the treatment tool inserted into the cavitycannot easily be manipulated. Thus, the subject tissue and thesurrounding tissues can easily be damaged.

As described above, the operator must pay great attention to protect thesubcutaneous tissue from being damaged when the operator treats aportion in the vicinity of the subcutaneous tissue, such as the bloodvessel and the nerve. However, the ablating operation and the incisingoperation, to be performed just above the saphenous vein intended to beextracted, have a risk of the saphenous vein being damaged by thetreatment tool or the like during the operation. The operation forforming a cavity under the skin has a similar risk. The saphenous veinfor use as a bypass blood vessel in the heart is required to beextracted while being protected from any damage. The foregoingrequirement is not limited to the extraction of the saphenous vein. Alsothe same requirement arises in any case where the tissues, which must beprotected, exist near the portion in which a treatment operation isperformed.

On the other hand, a technique has been developed which has anarrangement such that a hood is attached to the insertion portion of theendoscope to protect an observation window of the endoscope from beingcontaminated due to adhesion of the tissue of the organism to theobservation window and to form a space which permits an observation tobe performed with the endoscope when the tissue of the organism, such asthe subcutaneous tissue, having no cavity therein is observed andtreated by using the endoscope. The foregoing objects are importantfacts when the subcutaneous tissue is evulsed.

The applicant of the present invention has applied a sheath which servesas the hood to be attached to the insertion portion of the endoscope andwhich has a cylindrical shape having an opened leading end (refer toJapanese Patent Application No. 7-172466) published as Japanese PatentLaid-Open No. 8-117181, and a hood having a shape capable of completelycovering the endoscope and suitable to excise the tissue (refer toJapanese Patent Application No. 7-172139). Moreover, a hood has beendisclosed in Japanese Patent Publication No. 4-10328, the hood having anopening formed on the side surface thereof for permitting a treatmenttool, such as a knife, to be inserted through the opening. Another hoodhas been disclosed in WO94/11052, the hood having a tubular body, intowhich the endoscope is inserted and which has the end that can be openedfor permitting a visual field to be maintained for the endoscope whenthe observation and treatment are performed. In Japanese PatentPublication No. 4-17648, a hood having a window which can be opened andclosed for the treatment tool has been disclosed. In relation to thehoods disclosed as described above, a tracheal unit consisting of anouter tube and an internal needle has been disclosed in Japanese UtilityModel Publication No. 61-7686 (corresponding to Laid-Open PublicationNo. 56-166006, the internal needle of the tracheal unit having a HFelectrode attached thereto. In Japanese Patent Laid-Open No. 5-161660, atracheal unit having a transparent leading end has been disclosed. Thetracheal unit is combined with an endoscope and a laser beam unit.

As described above, in recent years, the treatment using an endoscopehas been performed in a portion in which no cavity exists, as has beenperformed when the blood vessel in the human body is treated. In thiscase, also a technique is employed in which any of the various hoods isattached to the insertion portion of the endoscope; and the endoscope ismoved forward while excising the portion between the tissues of theorganism having no cavity. If the hood abuts against, for example, thefasciae between muscles during the operation of inserting the endoscope,only a sluggish operation using the hood encounters a great difficultyin incising the fasciae. If bleeding takes place unintentionally duringthe operation for excising the tissue, hemostasis is required. However,the conventional techniques cannot smoothly solve the foregoingproblems.

That is, the technique disclosed in Japanese Patent Application No.7-172139 permits only a sluggish operation to be performed such that theleading end of the hood is forcibly inserted into the tissue of theorganism when, for example, an operation for incising the fasciaebetween the muscles is performed. Thus, the technique encounters aproblem in that the operation efficiency cannot be improved. Moreover,when hemostasis of a bleeding portion is intended, a complicatedoperation is required such that another hemostasis means is, inparallel, inserted between tissues. The hood disclosed in JapanesePatent Publication No. 4-10328 and having the opening in the sidesurface thereof cannot effectively incise and/or excise the tissue ofthe organism in front of the endoscope in the case where the treatmenttool, such as a knife, is inserted through the opening. Moreover, sinceno hemostasis means is provided, hemostasis of the bleeding portioncannot effectively be performed. Although the techniques disclosed inJapanese Patent Application Laid-Open No. 8-117181 Japanese PatentPublication No. 4-17648 and WO94/11052 are able to solve the foregoingproblems by inserting an incising tool and a hemostasis tool into thebody through the treatment tool channel of the endoscope, anotherproblem arises in that the operation for inserting and drawing thetreatment tool to and from the treatment tool channel of the endoscopeand the operations of the treatment tools are too complicated. Since thetechnique disclosed in WO94/11052 has the structure such that thetubular body into which the endoscope is inserted is not transparent,the excising operation is required to be blindly performed. Thus, theoperation cannot easily be completed and a problem arises in keepingsafety.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a system for evulsingsubcutaneous tissue which is capable of easily and safely evulsing thesubcutaneous tissue, represented by the subcutaneous blood vessel, suchas the saphenous vein, while observing the portion to be evulsed throughan endoscope.

The object of the present invention can be achieved by the followingsystem for evulsing subcutaneous tissue: that is, according to oneaspect of the present invention, there is provided a system for evulsingsubcutaneous tissue, comprising: an endoscope adapted to be insertedinto subcutaneous tissue through a skin cut portion in order to observetissue below the skin which is a subject to be evulsed; an excising(dissecting) unit adapted to be inserted into the subcutaneous tissuethrough the skin cut portion and capable of excising the tissue, whichis the subject to be evulsed, from surrounding tissue in order to form acavity along the tissue, which is the subject to be evulsed, and belowthe skin; a cavity maintaining unit adapted to be inserted into thecavity formed by the excising unit through the skin cut portion andretained in the cavity in order to maintain a treatment space by itselfaround the tissue, which is the subject to be evulsed, for permittingthe endoscope to be inserted and drawn and treatment of the tissue,which is the subject to be evulsed, to be performed; and at least onetreatment tool adapted to be inserted into the treatment spacemaintained by the cavity maintaining unit to perform the treatmentrequired to evulse the tissue, which is the subject to be evulsed, inthe treatment space.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention and, together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is diagram showing a state where a skin cut portion is formed inthe lower extremity to apply a system for evulsing subcutaneous tissueaccording to a first embodiment of the present invention;

FIG. 2A is a cross sectional view taken along line 2A--2A of FIG. 1;

FIG. 2B is a cross sectional view showing a state where an excisingmember has been inserted into the subcutaneous tissue and correspondingto FIG. 2A;

FIG. 2C is a cross sectional view showing a state where a tissueprotective tool has been inserted into the subcutaneous tissue andcorresponding to FIG. 2A;

FIG. 2D is a cross sectional view showing a state where the tissueprotective tool and a cavity forming tool have been inserted into thesubcutaneous tissue and corresponding to FIG. 2A;

FIG. 2E is a cross sectional view showing a state where a cavitymaintaining tool has been inserted into the subcutaneous tissue andcorresponding to FIG. 2A;

FIG. 3 is a side view showing a hard endoscope forming the system forevulsing subcutaneous tissue according to the first embodiment of thepresent invention;

FIG. 4A is a plan view showing the excising member forming the systemfor evulsing subcutaneous tissue according to the first embodiment ofthe present invention;

FIG. 4B is a vertical cross sectional view showing the excising membershown in FIG. 4A;

FIG. 4C is a front view showing the excising member shown in FIG. 4A;

FIG. 4D is a vertical cross sectional view showing the leading end ofthe excising member shown in FIG. 4A;

FIG. 4E is a cross sectional view taken along line 4E--4E shown in FIG.4D;

FIG. 4F is a cross sectional view taken along line 4F--4F shown in FIG.4D;

FIG. 4G is a cross sectional view taken along line 4G--4G shown in FIG.4D;

FIG. 5A is a plan view showing a sheath holder set to the endoscopetogether with the excising member;

FIG. 5B is a vertical cross sectional view showing an assembly set intothe state shown in FIG. 5A;

FIG. 6A is a vertical cross sectional view showing a state where anexcising operation is performed with the excising member;

FIG. 6B shows an image observed with the endoscope in the operationstate shown in FIG. 6A;

FIG. 7A is a perspective view showing the tissue protective tool formingthe system for evulsing subcutaneous tissue according to the firstembodiment;

FIG. 7B is a cross sectional view taken along line 7B--7B shown in FIG.7A;

FIG. 8A is a perspective view showing a connection portion between theexcising member and the tissue protective tool;

FIG. 8B is a vertical cross sectional view showing the connectionportion in a state where the excising member and the tissue protectivetool are connected to each other;

FIG. 9 is a perspective view showing a state where the tissue protectivetool has been inserted between skin cut portions;

FIG. 10A is perspective view showing a state where a dilator hook isconnected to a cavity forming tool;

FIG. 10B is a vertical cross sectional view showing the connectionportion in a state where the dilator hook has been connected to thecavity forming tool;

FIG. 10C is a plan view showing the connection portion in a state wherethe dilator hook has been connected to the cavity forming tool;

FIG. 11A is a rear view showing the cavity forming tool;

FIG. 11B is a cross sectional view taken along line 11B--11B shown inFIG. 11A;

FIG. 12 is a perspective view showing a state where the cavity formingtool is connected to the tissue protective tool inserted between theskin cut portions;

FIG. 13 is a perspective view showing the cavity maintaining tool;

FIG. 14A is a diagram showing a state where the tissue protective tooland the cavity maintaining tool have been inserted into the subcutaneoustissue;

FIG. 14B is a diagram showing a state where the cavity maintaining toolhas been inserted into the subcutaneous tissue;

FIG. 15A is a perspective view showing a state where the hard endoscopeand a treatment tool have been inserted into the cavity maintainingtool;

FIG. 15B is a perspective view showing a state where the hard endoscopeand the treatment tool have been inserted into the cavity maintainingtool;

FIG. 16 shows an image observed with the hard endoscope;

FIG. 17 shows an image observed with the hard endoscope;

FIG. 18 shows an image observed with the hard endoscope;

FIG. 19A shows an image observed with the hard endoscope to illustrate astate where a hook probe is used;

FIG. 19B shows an image observed with the hard endoscope to illustrate astate where the hook probe is used;

FIG. 20 is a perspective view showing a first example of the hook probe;

FIG. 21 a vertical cross sectional view showing the hook probe shown inFIG. 20;

FIG. 22A shows an image observed with the endoscope to illustrate astate where the hook probe shown in FIG. 20 is used;

FIG. 22B shows an image observed with the endoscope to illustrate astate where the hook probe shown in FIG. 20 is used;

FIG. 23A is a vertical cross sectional view showing a second example ofthe hook probe;

FIG. 23B is view showing the portion shown in FIG. 23A when viewed froma direction of an arrow 23B;

FIG. 24A is a vertical cross sectional view showing a third example ofthe hook probe;

FIG. 24B is a view showing the portion shown in FIG. 24A when viewedfrom a direction of an arrow 24B;

FIG. 25A is a vertical cross sectional view showing a first modificationof the excising member shown in FIGS. 4A to 4G;

FIG. 25B is a plan view showing the excising member shown in FIG. 25A;

FIG. 26A is a vertical cross sectional view showing a state where anexcising operation is performed with the excising member shown in FIG.25A;

FIG. 26B shows an image observed with the endoscope in the operationstate shown in FIG. 26A;

FIG. 27A is a perspective view showing a first modification of thetissue protective tool shown in FIG. 7A;

FIG. 27B is a cross sectional view taken along line 27B--27B shown inFIG. 27A;

FIG. 28A is a perspective view showing a second modification of thetissue protective tool and a first modification of the cavity formingtool;

FIG. 28B is a cross sectional view taken along line 28B--28B shown inFIG. 28A;

FIG. 28C is a cross sectional view taken along line 28C--28C shown inFIG. 28A;

FIG. 29 is a perspective view showing a first modification of the cavitymaintaining tool;

FIG. 30A is a front view showing the cavity maintaining tool shown inFIG. 29;

FIG. 30B is a vertical cross sectional view showing the cavitymaintaining tool shown in FIG. 29;

FIG. 31A is a perspective view showing a state where the cavitymaintaining tool shown in FIG. 29 is used;

FIG. 31B is a perspective view showing a state where the cavitymaintaining tool shown in FIG. 29 is used;

FIG. 32 is cross sectional view showing a state of treatment to beperformed before the cavity maintaining tool shown in FIG. 29 isretained below the skin;

FIG. 33 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 34 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 35 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 36 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 37 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 38 shows an image observed with the endoscope to illustrate a statein the cavity formed by the cavity maintaining tool shown in FIG. 29;

FIG. 39 is a perspective view showing a second modification of thecavity maintaining tool;

FIG. 40 is a perspective view showing a cavity maintaining tool and aninsertion helper according to a third modification;

FIG. 41 is a perspective view showing a state where the insertion helperhas been attached to the cavity maintaining tool shown in FIG. 40;

FIG. 42A is a perspective view showing a cavity maintaining tool and aninsertion helper according to a fourth modification;

FIG. 42B is a perspective view showing a state where the insertionhelper has been attached to the cavity maintaining tool shown in FIG.42A;

FIG. 43 is a cross sectional view taken along line 43--43 shown in FIG.42B;

FIG. 44 is a perspective view showing a fifth modification of the cavitymaintaining tool;

FIG. 45A is a perspective view showing a cavity maintaining toolaccording to a sixth modification when viewed from an upper position;

FIG. 45B is a perspective view showing the cavity maintaining tool shownin FIG. 45A when viewed from a lower position;

FIG. 46A is a perspective view showing a seventh modification of thecavity maintaining tool;

FIG. 46B is a cross sectional view showing a state where the cavitymaintaining tool shown in FIG. 46A is retained below the skin;

FIG. 47 is a perspective view showing an eighth modification of thecavity maintaining tool;

FIG. 48A is a perspective view showing a ninth modification of thecavity maintaining tool;

FIG. 48B is a perspective view showing a state where the cavitymaintaining tool shown in FIG. 48A is used:

FIG. 49 is a perspective view showing a tenth modification of the cavitymaintaining tool;

FIG. 50 is a perspective view showing an insertion helper to be usedtogether with a cavity maintaining tool according to an eleventhmodification;

FIG. 51A is a vertical cross sectional view showing the insertion helpershown in FIG. 50;

FIG. 51B is a vertical cross sectional view showing a state where thecavity maintaining tool according to the eleventh modification has beenattached to the insertion helper shown in FIG. 50;

FIG. 52 is a perspective view showing a state where the cavitymaintaining tool according to the eleventh modification is used;

FIG. 53 is a perspective view showing a state where the cavitymaintaining tool according to the eleventh modification is used;

FIG. 54 is a perspective view showing a state where the cavitymaintaining tool according to the eleventh modification is used;

FIG. 55 is a perspective view showing a modification of theattaching/detaching means according to the eleventh modification;

FIG. 56A is a front view showing the attaching/detaching means shown inFIG. 55;

FIG. 56B is a side view showing the attaching/detaching means shown inFIG. 55;

FIG. 57 is a perspective view showing a state where the cavitymaintaining tool according to a twelfth modification is used;

FIG. 58 shows an image observed with the endoscope in a state where thecavity maintaining tool according to the twelfth modification is used;

FIG. 59 shows an image observed with the endoscope in a state where thecavity maintaining tool according to the twelfth modification is used;

FIG. 60A is a perspective view showing an assembled state of the cavitymaintaining tool according to a thirteenth modification;

FIG. 60B is an exploded perspective view showing the cavity maintainingtool according to the thirteenth modification;

FIG. 60C is an exploded cross sectional view showing the cavitymaintaining tool according to the thirteenth modification;

FIG. 61A is an assembled perspective view showing a cavity maintainingtool according to a fourteenth modification;

FIG. 61B is an exploded perspective view showing the cavity maintainingtool according to the fourteenth modification;

FIG. 62A is an assembled perspective view showing a cavity maintainingtool according to a fifteenth modification;

FIG. 62B is an exploded perspective view showing the cavity maintainingtool according to the fifteenth modification;

FIG. 62C shows a first example of a connection means for connecting aninsertion helper and the body, forming the cavity maintaining toolaccording to the fifteenth modification, to each other;

FIG. 62D is a front view showing the insertion helper shown in FIG. 62C;

FIG. 62E shows a second example of the connection means for connectingthe insertion helper and the body, forming the cavity maintaining toolaccording to the fifteenth modification, to each other;

FIG. 62F is a front view showing the insertion helper shown in FIG. 62E;

FIG. 62G shows a third example of the connection means for connectingthe insertion helper and the body, forming the cavity maintaining toolaccording to the fifteenth modification, to each other;

FIG. 62H is a front view showing the insertion helper shown in FIG. 62G;

FIG. 62I shows a first example of an opening of an endoscope guide tubeprovided for the body of the cavity maintaining tool according to thefifteenth modification;

FIG. 62J shows a second example of the opening of the endoscope guidetube provided for the body of the cavity maintaining tool according tothe fifteenth modification;

FIG. 63A is an assembled perspective view showing a cavity maintainingtool according to a sixteenth modification;

FIG. 63B is an exploded perspective view showing the cavity maintainingtool according to the sixteenth modification;

FIG. 64A is an assembled perspective view showing a cavity maintainingtool according to a seventeenth modification;

FIG. 64B is an exploded perspective view showing the cavity maintainingtool according to the seventeenth modification;

FIG. 65A is a perspective view showing a first example of a guide memberfor protecting the subcutaneous tissue while guiding pincers;

FIG. 65B is a cross sectional view taken along line 65B--65B shown inFIG. 65A;

FIG. 65C is a side cross sectional view showing the guide member shownin FIG. 65A;

FIG. 66A is a diagram showing a state where the guide member shown inFIG. 65A has been inserted between the saphenous vein and the connectivetissue;

FIG. 66B is a side cross sectional view of FIG. 66A;

FIG. 67A is a diagram showing a state where the saphenous vein and theconnective tissue are excised by using the guide member shown in FIG.65A;

FIG. 67B is a side cross sectional view of FIG. 67A;

FIG. 67C is a cross sectional view taken along line 67C--67C shown inFIG. 67B;

FIG. 68A is a diagram showing a state where the connective tissue is cutby using the pincers guided by the guide member shown in FIG. 65A;

FIG. 68B is a side cross sectional view of FIG. 68A;

FIG. 69A is a perspective view showing a second example of the guidemember;

FIG. 69B is horizontal cross sectional view showing the guide membershown in FIG. 69A;

FIG. 69C is a vertical cross sectional view showing the guide membershown in FIG. 69A;

FIG. 70 is a perspective view showing a third example of the guidemember;

FIG. 71A is a horizontal cross sectional view showing the guide membershown in FIG. 70;

FIG. 71B is a vertical cross sectional view showing the guide membershown in FIG. 70;

FIG. 71C is a plan view showing the guide member shown in FIG. 70;

FIG. 72A is a diagram showing a state where the connective tissue is cutby using the guide member and the treatment tool shown in FIG. 70;

FIG. 72B is a side cross sectional view of FIG. 72A;

FIG. 73 is a side cross sectional view showing a second modification ofthe excising member;

FIG. 74 is a side cross sectional view showing a state where a balloonof the excising member shown in FIG. 73 has been expanded;

FIG. 75 is a side cross sectional view showing a modification of theexcising member shown in FIG. 73;

FIG. 76 is a diagram showing a state of the system for evulsingsubcutaneous tissue according to a second embodiment of the presentinvention where the excising member is inserted through either of theskin cut portions while being moved along a groove in the top surface ofthe tissue protective tool to reach the residual skin cut portion;

FIG. 77 is a diagram showing a state where the excising member formingthe system for evulsing subcutaneous tissue according to the secondembodiment is inserted through either of the skin cut portions whilebeing moved along a groove in the top surface of the tissue protectivetool to reach the residual skin cut portion;

FIG. 78 is a side view showing the excising member forming the systemfor evulsing subcutaneous tissue according to the second embodiment;

FIG. 79 is an exploded perspective view showing a cavity maintainingtool forming the system for evulsing subcutaneous tissue according tothe second embodiment;

FIG. 80 is a perspective view showing an insertion helper for guidingand helping insertion of an outer tube of the cavity maintaining toolshown in FIG. 79;

FIG. 81 is a side cross sectional view showing a state where theinsertion helper shown in FIG. 80 is attached to the outer tube of thecavity maintaining tool shown in FIG. 79;

FIG. 82 is a perspective view showing a state where the outer tube ofthe cavity maintaining tool shown in FIG. 79 has been inserted into thesubcutaneous tissue;

FIG. 83 is a diagram showing a state where an inner tube is insertedinto the outer tube in a state shown in FIG. 82;

FIG. 84A is a vertical cross sectional view of FIG. 83;

FIG. 84B is a cross sectional view taken along line 84B--84B shown inFIG. 84A;

FIG. 84C is a cross sectional view taken along line 84C--84C shown inFIG. 84A;

FIG. 85A is a vertical cross sectional view showing a state where thehard endoscope has been inserted into the inner tube in the state shownin FIG. 84A;

FIG. 85B shows an image observed with the endoscope in the state shownin FIG. 85A;

FIG. 86A is a vertical cross sectional view showing a state where thehook probe has been inserted into the inner tube in the state shown inFIG. 85A;

FIG. 86B shows an image observed with the endoscope in the state shownin FIG. 86A;

FIG. 87 is a schematic view showing the structure of the endoscopesystem;

FIG. 88A shows an image observed by the endoscope;

FIG. 88B shows an image observed by the endoscope;

FIG. 88C shows an image observed by the endoscope;

FIG. 89 is a perspective view showing a cavity maintaining toolaccording to a first modification of the second embodiment;

FIG. 90A is a vertical cross sectional view showing a state where thehard endoscope has been inserted into the inner tube in a state wherethe cavity maintaining tool shown in FIG. 89 has been inserted into thesubcutaneous tissue;

FIG. 90B shown an image observed by the endoscope in the state shown inFIG. 90A;

FIG. 91A is an exploded perspective view showing a cavity maintainingtool according to a second modification of the second embodiment;

FIG. 91B is a vertical cross sectional view showing the cavitymaintaining tool shown in FIG. 91A in an assembled state;

FIG. 92 is a perspective view showing the outer tube of a cavitymaintaining tool according to a third Modification of the secondembodiment;

FIG. 93 is an exploded perspective view showing the cavity maintainingtool according to the third modification of the second embodiment;

FIG. 94 is a side cross sectional view showing a state where theinsertion helper shown in FIG. 80 has been attached to the outer tubeshown in FIG. 92;

FIG. 95 is a perspective view showing a state where the outer tube ofthe cavity maintaining tool shown in FIG. 92 has been inserted into thesubcutaneous tissue;

FIG. 96 is a diagram showing a state where the inner tube has beeninserted into the outer tube in the state shown in FIG. 95;

FIG. 97A is a vertical cross sectional view of FIG. 96;

FIG. 97B is a cross sectional view taken along line 97B--97B shown inFIG. 97A;

FIG. 97C is a cross sectional view taken along line 97C--97C shown inFIG. 97A;

FIG. 98A is a vertical cross sectional view showing a state where thehard endoscope has been inserted into the inner tube in the state shownin FIG. 97A;

FIG. 98B shows an image observed with the endoscope in the state shownin FIG. 98A;

FIG. 99A is a vertical cross sectional view showing a state where thehook probe has been inserted into the inner tube in the state shown inFIG. 98A;

FIG. 99B shown an image observed with the endoscope in the state shownin FIG. 99A;

FIG. 100 is a perspective view showing a cavity maintaining toolaccording to a fourth modification of the second embodiment;

FIG. 101A is a vertical cross sectional view showing a state where thehard endoscope has been inserted into the inner tube in the state wherethe cavity maintaining tool shown in FIG. 100 has been inserted into thesubcutaneous tissue;

FIG. 101B shows an image observed with the endoscope in the state shownin FIG. 101A;

FIG. 102A is an exploded perspective view showing a cavity maintainingtool according to a fifth modification of the second embodiment;

FIG. 102B is a vertical cross sectional view showing a state where thecavity maintaining tool shown in FIG. 102A has been assembled;

FIG. 103A is a plan view showing a modification of the excising memberaccording to the first embodiment;

FIG. 103B is a vertical cross sectional view of FIG. 103A;

FIG. 104A is a plan view showing a sheath holder according to amodification of the first embodiment which has been set to the endoscopetogether with the excising member shown in FIG. 103A;

FIG. 104B is a vertical cross sectional view showing an assembly set asshown in FIG. 104A;

FIG. 105A is a perspective view showing a modification of the cavitymaintaining tool according to the first embodiment;

FIG. 105B is a front view showing the cavity maintaining tool shown inFIG. 105A;

FIG. 105C is a vertical cross sectional view showing the cavitymaintaining tool shown in FIG. 105A;

FIG. 106 is a cross sectional view showing a first embodiment of a hoodfor an endoscope;

FIG. 107A is a perspective view showing the leading end of the hood foran endoscope shown in FIG. 106;

FIG. 107B is a vertical cross sectional view showing a state whereexcision of tissue is performed by using the hood for an endoscope shownin FIG. 106;

FIG. 107C is a vertical cross sectional view showing a state where thehood has been opened after the excision of tissue has been performed byusing the hood for an endoscope shown in FIG. 106;

FIG. 107D shows an image obtained with the endoscope in the state shownin FIG. 107B;

FIG. 107E shows an image obtained with the endoscope in the state shownin FIG. 107C;

FIG. 108A is a vertical cross sectional view showing a second embodimentof the hood for an endoscope;

FIG. 108B is a vertical cross sectional view showing a third embodimentof the hood for an endoscope;

FIG. 108C is a vertical cross sectional view showing a fourth embodimentof the hood for an endoscope;

FIG. 109 is a vertical cross sectional view showing a fifth embodimentof the hood for an endoscope;

FIG. 110A is a perspective view showing a sixth embodiment of the hoodfor an endoscope;

FIG. 110B is a vertical cross sectional view showing a state where theopening at the leading end of the hood for an endoscope shown in FIG.110A is closed;

FIG. 110C is a horizontal cross sectional view showing an engravedstripe portion of the hood for an endoscope shown in FIG. 110A;

FIG. 110D is a vertical cross sectional view showing a state where theopening at the leading end of the hood for an endoscope shown in FIG.110A is opened;

FIG. 111A is a vertical cross sectional view showing a seventhembodiment of the hood for an endoscope;

FIG. 111B is a vertical cross sectional view showing a state where ashutter member of the hood for an endoscope shown in FIG. 111A isopened;

FIG. 112 is cross sectional view taken along line 112--112 shown in FIG.111A;

FIG. 113A is a vertical cross sectional view showing a state whereobservation is performed through the opening of a transparent sheath ofthe hood for an endoscope according to an eighth embodiment; and

FIG. 113B is a vertical cross sectional view showing a state whereobservation is performed through the transparent portion of thetransparent sheath of the hood for an endoscope according to the eighthembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, preferred embodiments of the presentinvention will now be described with reference to the drawings.

FIGS. 1 to 19B show a first embodiment of the present invention. Priorto describing a system for evulsing subcutaneous tissue according tothis embodiment, a procedure for evulsing the blood vessel in the lowerextremity by the system for evulsing subcutaneous tissue according tothis embodiment by means of an endoscope will now be described withreference to FIGS. 1 and 2E.

FIG. 1 shows the lower extremity. When a blood vessel (hereinaftersimply called as "blood vessel"), such as the saphenous vein extendingfrom the inguinal region A of the thigh to the knee D and intended to beevulsed, is evulsed, a skin cut portion E1 is, by a knife or the like,formed in the inguinal region A of the thigh at a position just abovethe blood vessel C. Then, the blood vessel C is exposed through the skincut portion E1 by a pair of peeling forceps or the like. Then, thetissue just above the blood vessel C is dissected similarly by a pair ofpeeling forceps for a distance which can be observed by the naked eyethrough the skin cut portion E1.

FIG. 2A is a cross sectional view taken along line 2A--2A shown inFIG. 1. Referring to FIG. 2E, reference numeral 100 represents a skin,200 represents a subcutaneous tissue and 300 represents a connectivetissue on the blood vessel C. The blood vessel C exists below theconnective tissue 300 on the blood vessel C. When the blood vessel C isevulsed in the state shown in FIG. 2A, the excising member 10 shown inFIG. 4A is used to separate the blood vessel C and the surroundingtissues from each other so that cavity G is formed, as shown in FIG. 2B.In the foregoing case, the hard endoscope 20 shown in FIG. 3 is insertedinto the excising member 10 followed by being secured. Then, the leadingend of the excising member 10 is, through the skin cut portion E1 in theinguinal region A, inserted along the portion above the blood vessel Ctoward the knee D. Since the leading end of the excising member 10 ismade of a transparent member, the blood vessel C and its side branch Fcan clearly be observed through the hard endoscope 20 during theforegoing process. The excising member 10 is inserted gradually in sucha manner that the excising member 10, slightly, is moved forward andrearward while observing the movement of blood vessel C through the hardendoscope 20. As a result, the excising member 10 is inserted to aposition near the knee D along the blood vessel C. Then, the skin justabove the leading end of the excising member 10 is incised so that skincut portion E2 is formed, followed by penetrating the leading end of theexcising member 10 to the outside of the body through the skin cutportion E2.

Then, while leaving the excising member 10 in the body, the hardendoscope 20 is drawn, and then a tissue protective tool 30 shown inFIG. 7A is attached to the side portion of the excising member 10adjacent to the operator, which is positioned near the skin cut portionE1 in the inguinal region A. Then, while drawing, to the outside, theexcising member 10 through the skin cut portion E2 above the knee D, thetissue protective tool 30 is introduced into the cavity G dissected bythe excising member 10 so that a state shown in FIG. 2C is realized.Note that the tissue protective tool 30 can be inserted without a heavyload because the widthwise cross sectional area of the tissue protectivetool 30 is substantially the same as the widthwise cross sectional areaof the excising member 10. The tissue protective tool 30 is separatedfrom the excising member 10 after the end portion of the excising member10 adjacent to the operator's hand has been pulled out through the skincut portion E2, the tissue protective tool 30 being then retained in thecavity G.

Then, a cavity forming tool (cavity expansion means) 50 shown in FIG.11A is used to expand the cavity G. In the foregoing case, the cavityforming tool 50 is, as shown in FIG. 2D, introduced into the cavity G ina state where a projection 52 of the cavity forming tool 50 is receivedin a groove 30a in the upper surface of the tissue protective tool 30.The cavity forming tool 50 is introduced into the cavity G by means of adilator hook 101 having a tapered leading end, the diameter of which isreduced toward the leading end, as shown in FIG. 10A. As shown in FIG.11A, the cavity forming tool 50 is formed into a substantially rhombicshape having a flat leading end. A plurality of cavity forming tools,for example, 50a to 50d are prepared to serve as the cavity forming tool50 respectively having various widths. When the cavity G is expanded byusing the cavity forming tool 50, initially the dilator hook 101 isinserted to the skin cut portion E1 of the inguinal region A through theskin cut portion E2 above the knee D. Then, the cavity forming tool 50ahaving the smallest width is attached to the leading end of the dilatorhook 101 protruding to the outside through the skin cut portion E1.Then, the operator holds the handle of the dilator hook 101 to pull thedilator hook 101 so that the cavity forming tool 50a is slowlyintroduced into the cavity G through the skin cut portion E1 in theinguinal region A while moving the projection 52 of the cavity formingtool 50a along the groove 30a of the tissue protective tool 30. Then,the cavity forming tool 50a is pulled out to the outside through theskin cut portion E2 above the knee D. Then, in a similar procedure, thecavity forming tools 50b to 50d, the widths of which are enlarged inthis sequential order, are sequentially inserted and pulled out to andfrom the cavity G. As a result, the cavity G is expanded by stage. Notethat the size of the cut portion of each of the skin cut portion E1 andskin cut portion E2 is determined to be the size which permits thecavity forming tool 50 having the largest width (for example, 50d) to beinserted.

After the foregoing operation has been completed, the cavity maintainingtool 60 is retained in the expanded cavity G so that the cavity G ismaintained, as shown in FIG. 2E. In the foregoing state, the bloodvessel C is exposed into the cavity G maintained by the cavitymaintaining tool 60. In this state, the hard endoscope 20 is insertedinto a guide tube 62f of the cavity maintaining tool 60 to observe theoverall body of the cavity G. Due to the observation above, the bloodvessel C is completely exposed in a case where the excising member 10has passed through a layer just above the blood vessel C. In a casewhere the excising member 10 passes through the blood vessel C through amembrane tissue, the upper portion of the blood vessel C is covered withthe connective tissue 300 on the blood vessel C. Therefore, theconnective tissue 300 on the blood vessel C is required to initially beremoved in the foregoing case. The removal of the connective tissue 300on the blood vessel C will be described later.

Then, the system for evulsing subcutaneous tissue according to thisembodiment will now be described in detail.

FIG. 3 shows the hard endoscope 20. As shown in FIG. 3, the hardendoscope 20 comprises a hard insertion portion 2 including anobservation optical system and an irradiation optical system; and anendoscope body 4 disposed at the base portion of the insertion portion 2and having a connection portion 3 to be connected to the endoscope unit.An axial member 8 extends from the body 4. The insertion portion 2 hasthe leading end at which a leading end section 5 having an inclined typeobservation window inclined with respect to the axial line of theinsertion portion 2 and an irradiation window is formed. The endoscopebody 4 has a connector 7 which is connected to a light guide cable (notshown).

FIGS. 4A to 4G show the excising member 10. As shown in FIG. 4A, theexcising member 10 comprises a body 11 formed into an elongated tubeinto which the hard endoscope 20 can be inserted; a large-diameter pipe13 formed in the body 11 at a position adjacent to the operator's hand;and a transparent leading end 12 connected to the leading end of thebody 11 and arranged to cover the leading end section 5 of the hardendoscope 20. The large-diameter pipe 13 has a slit 13a to which atissue protective tool 30, to be described later, can be hooked.

As shown in FIGS. 4B to 4D, the leading end 12 is formed into acylindrical cap made of a transparent synthetic resin and having a crosssection which is completely closed as shown in FIGS. 4E to 4G. A ridgeportion 16 between a slope 15a of the leading end 12 and an observationportion 15b is formed into a moderate shape to protect the blood vesselfrom being damaged. As a result of the performed investigation, theridge portion 16 is required to be formed into a round shape having acurvature radius of at least 1 mm or larger, preferably 3 mm. If thecurvature radius of the ridge portion 16 is too small, there arises arisk that the blood vessel is cut unintentionally, in particular, thebranch blood vessel is cut unintentionally.

The excising member 10 is arranged to satisfy .o slashed.A>.o slashed.Bassuming that the diameter of the leading end 12 is .o slashed.A andthat of the body 11 is .o slashed.B. The axial length of the leading end12 is about 20 mm. As a result of the investigation, the structure that.o slashed.A is about 9 mm and .o slashed.B is about 6.5 mm enables theportion surrounding the blood vessel to efficiently be dissected whileprotecting the blood vessel from being damaged. The large-diameter pipe13 is engaged to a sheath holder 110 shown in FIGS. 5A and 5B, thelarge-diameter pipe 13 having diameter .o slashed.C which is smallerthan the diameter .o slashed.A of the leading end 12.

As shown in FIGS. 5A and 5B, the sheath holder 110 is slid along theouter surface of the insertion portion 2 of the hard endoscope 20 fromthe portion adjacent to the leading end of the insertion portion 2 sothat the sheath holder 110 is attached to the endoscope body 4. A lightconnector 7 of the hard endoscope 20 has a cap adapter 81 at the mouthportion thereof so as to be connected to an arbitrary and conventionalcable. In the foregoing case, the outer diameter of the connector 7 isset to diameter d, while the outer diameter of the cap adapter 81 is setto diameter D when connected to the connector 7 (see FIG. 5A). Thesheath holder 110 has, in the base portion thereof, a joint 82. Thejoint 82 is formed into purse-like shape having an opened rear end andwide body portion. The diameter of the narrowest portion of the openedportion is set to diameter W₁. The maximum diameter of the wide bodyportion of the joint 82 is set to diameter W₂ so as to insert a capadapter 81 therein. The diameters have a relationship expressed as W₂>D>W₁ >d. That is, in the state where the cap adapter 81 has beenattached to the connector 7, the sheath holder 110 cannot be attached tothe endoscope body 4. In a state where the cap adapter 81 has beenremoved from the connector 7, the sheath holder 110 is attached to theendoscope body 4. Then, the cap adapter 81 is attached to the connector7 so that the sheath holder 110 is fixedly attached to the endoscopebody 4.

As shown in FIG. 5B, the sheath holder 110 has a joining port 83 at aposition near the leading end thereof to receive the excising member 10.Moreover, a fixing screw 84 for fixing the excising member 10 is,together with a C-ring 85, disposed above the joining port 83. Thus, theleading end of the fixing screw 84 can be engaged to an engaging opening86 formed in the large-diameter pipe 13 of the excising member 10. Thesheath holder 110 has an opening in its portion which runs parallel tothe portion in which the fixing screw 84 is inserted. A control pin 87for controlling rotation of the excising member 10 is, from outside,inserted into the opening to project into a joining port 83. Theprojection portion of the control pin 87 projecting into the joiningport 83 is received in a rotation-stopping groove 17 formed in thelarge-diameter pipe 13 of the excising member 10. As a result, when theexcising member 10 is attached to the hard endoscope 20, the position ofthe excising member 10 in the rotational direction can automatically bedetermined. When the excising member 10 and the sheath holder 110 havebeen attached to the hard endoscope 20 as described above, as shown nFIG. 4B, the leading end section 5 of the hard endoscope 20 is placed toa position near the leading end of the leading end 12 of the excisingmember 10. In this state, observation by means of the hard endoscope 20through the observation portion 15b is permitted in such a manner thatthe observation direction O of the hard endoscope 20 is diagonallydownward. In this case, the slope 15a of the leading end 12 is directedto diagonally upward with respect to the axis of the insertion portion 2of the hard endoscope 20.

FIG. 6A shows a state where the excising member 10 has been attached tothe hard endoscope 20 and inserted into the skin cut portion E1. Theleading end 12 of the excising member 10 is, through the skin cutportion E1, inserted into the connective tissue 300 on the blood vesselC or the subcutaneous fat layer 200 near the blood vessel C and existingbetween the skin 100 and the blood vessel C. An image observed with thehard endoscope 20 is shown in FIG. 6B. As shown in FIG. 6B, the leadingend 12 of the excising member 10 and the blood vessel C including theconnective tissue 300 on the blood vessel C is included in the visualfield of the hard endoscope 20 (symbol F represents a branch of bloodvessel C). When the excising member 10 is moved forward in the foregoingstate, the blood vessel C is dissected from the connective tissue 300 onthe blood vessel C so that the blood vessel C is exposed. Also thebranch F existing at an intermediate position of the blood vessel C isexposed. Thus, the blood vessel C and the branch F are included in thevisual field of the hard endoscope 20. If the ridge portion 16 betweenthe observation portion 15b and the slope 15a of the leading end 12 ofthe excising member 10 has an edge, the branch F can be cutunintentionally. However, the structure of this embodiment in which theridge portion 16 is rounded to have a curvature radius of about 3 mmprevents the branch F from being cut. Since the diameter (.o slashed.A)of the leading end 12 is a small diameter of about 9 mm, the bloodvessel C and the branch F can be protected from being applied with anexcessively heavy load when the excising member 10 is inserted along theblood vessel C. Therefore, the excising member 10 can safely be insertedinto the subcutaneous portion. Thus, the blood vessel C and theconnective tissue 300 on the blood vessel C can be dissected from eachother while observing the blood vessel C with the hard endoscope 20.

After the excising member 10 has been inserted along the blood vessel Cto cover the overall length of the evulsed region, the position of theleading end 12 of the excising member 10 is confirmed through the skin100. The skin cut portion E2 is formed just above the leading end 12 ofthe excising member 10 so that the leading end 12 of the excising member10 is projected through the skin cut portion E2. Then, the fixing screw84 of the sheath holder 110 is loosened to remove the hard endoscope 20from the excising member 10. Then, only the excising member 10 isretained in such a manner that the excising member 10 penetrates theportion from the skin cut portion E1 to the skin cut portion E2.

The tissue protective tool 30 will now be described with reference toFIGS. 7A and 7B. As shown in FIG. 7A, the tissue protective tool 30comprises an elongated protective tool body 31 formed into a plate-likeshape which can be inserted into the subcutaneous tissue; and flanges 32projecting at the base portion of the protective tool body 31 into thewidthwise direction. The protective tool body 31 has a width capable ofcovering the subcutaneous tissue which is required to be protected. Thelength of the protective tool body 31 is made to be somewhat longer thanthat of each of the skin cut portion E1 and skin cut portion E2. Theflanges 32 project to have the width with which the flanges 32 can notbe inserted into the subcutaneous tissue through the skin cut portionE1. A protective surface of the protective tool body 31 for covering thesubcutaneous tissue required to be protected, that is, the lower surfaceis formed into a smooth flat surface without any projections and pits. Asurface opposite to the protective surface that is, an upper surface hasa groove 30a formed to cover the overall length of the upper surface inthe axial direction of the protective tool body 31. In order to easilyinsert the tissue protective tool 30 into the subcutaneous tissue, theleading portion of the tissue protective tool 30 is tapered, the size ofwhich is reduced in the forward direction. In order to protect thetissue from being damaged, the leading end of the protective tool body31 is formed into a smooth and moderate shape.

FIGS. 8A and 8B show a method of connecting the tissue protective tool30 and the excising member 10 to each other. The leading portion of thetissue protective tool 30 has a connection hole 31a which can detachablybe hooked by the slit 13a of the excising member 10. In the case wherethe tissue protective tool 30 is used to cover and protect thesubcutaneous tissue which is the subject of the protection, theconnection hole 31a of the tissue protective tool 30 is connected to theslit 13a of the excising member 10 projecting over the skin cut portionE1. In this state, the leading end 12 of the excising member 10projecting over the skin cut portion E2 is pulled to pull out theexcising member 10 from the subcutaneous tissue. Moreover, the tissueprotective tool 30 is pulled into the dissected cavity between the bloodvessel C and the connective tissue 300 on the blood vessel C. By makingthe cross sectional area of the tissue protective tool 30 to be smallerthan that of the excising member 10, the tissue protective tool 30 caneasily be inserted between the blood vessel C and the connective tissue300 on the blood vessel C. FIG. 9 shows a state where the tissueprotective tool 30 has been, in place of the excising member 10,inserted between the blood vessel C and the connective tissue 300 on theblood vessel C, followed by being retained there. In the foregoingstate, the excising member 10 has been removed from the tissueprotective tool 30 and the blood vessel C is completely covered by theprotective surface of the tissue protective tool 30, from an upperposition.

FIGS. 10A to 10C show the dilator hook 101 for pulling the cavityforming tool 50 shown in FIG. 11A into the cavity G. The dilator hook101 has a leading end 40a formed into a shape inclined towards theforward position. Therefore, when the dilator hook 101 is inserted intothe subcutaneous tissue along the groove 30a of the tissue protectivetool 30, the leading end 40a cannot be caught by the subcutaneoustissue. The leading end 40a of the dilator hook 101 has a hook 40b to beconnected to the cavity forming tool 50. The cavity forming tool 50 hasa connection hole 51 to be engaged to the hook 40b of the dilator hook101. Note that the hook 40b and the connection hole 51 can be connectedto each other in only a direction in which the longitudinal axial lineof the cavity forming tool 50 has been rotated by an angular degree ofabout 90° with respect to the longitudinal axial line of the dilatorhook 101. In a state where the dilator hook 101 is connected to thecavity forming tool 50 shown in FIGS. 10B and 10C, the dilator hook 101is, along the groove 30a of the tissue protective tool 30, introducedinto the cavity through the skin cut portion E2, as shown in FIG. 12.The leading end 40a is allowed to project through the skin cut portionE1. Then, the smallest cavity forming tool 50a is attached to theleading end leading end 40a of the dilator hook 101. Therefore, when thedilator hook 101 is pulled in the foregoing state, the cavity formingtool 50a is pulled into the dissected space between the blood vessel Cand the connective tissue 300 on the blood vessel C. At this time, thecavity forming tool 50 is, as shown in FIG. 2D, pulled in such a mannerthat the projection 52 formed in the lower surface of the cavity formingtool 50 in the longitudinal direction of the same is guided by thegroove 30a of the tissue protective tool 30. As a result, the dissectedportion between the blood vessel C and the connective tissue 300 on theblood vessel C is expanded by the expansion portion 38 of the cavityforming tool 50a. Thus, a cavity wider than the cavity formed by theexcising member 10 is formed above the blood vessel C, that is, abovethe tissue protective tool 30. After the minimum cavity forming tool 50ahas reached the skin cut portion E2, the cavity forming tool 50a isremoved from the dilator hook 101. Then, the cavity forming tool 50bhaving a second size is attached to the dilator hook 101, followed bybeing, similarly to the cavity forming tool 50a, inserted through theskin cut portion E1 to the skin cut portion E2. The foregoing operationis performed until the largest cavity forming tool 50d is inserted.After the largest cavity forming tool 50d has formed the cavity G havinga predetermined size above the blood vessel C, the cavity G ismaintained by a cavity maintaining tool 60 to be described below.

FIG. 13 shows the cavity maintaining tool 60. The cavity maintainingtool 60 comprises an insertion helper 61 and a body 62 which can beexploded into individual parts. Note that the insertion helper 61 andthe body 62 are made of a synthetic resin or stainless steel. Shafts62e, by a number suitable to maintain the cavity, and an endoscope guidetube 62f for holding the endoscope are arranged between bases 62c of thebody 62 of the cavity maintaining tool 60. The shafts 62e and theendoscope guide tube 62f are formed into a frame structure runningparallel to the axial direction of the body 62. The bases 62c of thebody 62 formed in the longitudinal direction are formed into the samearch forms each including openings 62a in the lower portion thereof forthe purpose of smoothly inserting the treatment tool. The endoscopeguide tube 62f is arranged on the rear portion of the central portion ofthe bases 62c, while the plural shafts 62e are arranged between legs 63of the bases 62c. Since the shafts 62e and the endoscope guide tube 62fform a frame structure running parallel to the axial direction of thebody 62, a plurality of large horizontal openings 62h are formed in theside portion of the body 62, the horizontal openings 62h being connectedto a hollow portion 62g.

Pin-type locating members 64 for locating the insertion helper 61project over the front wall in the lower portion of the two leg portions63 of the front base 62c. The two end surfaces, the lower surface andthe side surface in the longitudinal direction, which come in contactwith the subcutaneous tissue to be protected, of the body 62 are roundedto remove edge portions. The endoscope guide tube 62f of the body 62 hastwo longitudinal ends which are formed into openings 62b. Moreover, anintermediate portion of the endoscope guide tube 62f is opened to facethe hollow portion 62g on the inside of the body 62.

The insertion helper 61 is formed into a semi-conical shape having arounded leading end. The lower surface of the insertion helper 61 isformed into a flat surface to have a hollow formed in the insertionhelper 61. A leading portion 61a of the insertion helper 61 has a guideconvex portion 61b so as to be guided to the subject tissue. The guideconvex portion 61b is allowed to slightly project over the lower surfaceof the insertion helper 61. When the cavity maintaining tool 60 isretained in the subject subcutaneous tissue, the guide convex portion61b is received in the groove 30a of the tissue protective tool 30,which has been inserted. The leading end portion 61a of the insertionhelper 61 is received in the groove 30a of the tissue protective tool 30when combined with the tissue protective tool 30. The insertion helper61 has locating holes 61c in the lower portion of the trailing endthereof, the locating holes 61c being arranged to receive the locatingmembers 64 of the body 62. The insertion helper 61 has an elastic member61d in the upper portion of the trailing end thereof, the elastic member61d being arranged to serve as a connection member to be engaged andsecured to the body 62. The elastic member 61d consists of a projection65 and an O-ring 66 attached around the projection 65. The elasticmember 61d is inserted and fastened in the opening of a front opening62b of the endoscope guide tube 62f so as to secure the insertion helper61 and the body 62. The front opening 62b of the endoscope guide tube62f has a groove shape to satisfactorily receive the elastic member 61din the form of a projection.

As described above, the cavity maintaining tool 60 is structured suchthat the locating members 64 of the body 62 are received by the locatingholes 61c of the insertion helper 61 so as to be engaged to the locatingholes 61c. Moreover, the elastic member 61d of the insertion helper 61is inserted and engaged to the front opening 62b of the endoscope guidetube 62f of the body 62. Thus, the body 62 and the insertion helper 61are combined to each other. As a result of the foregoing structure, theinsertion helper 61 can easily be removed from the body 62 whilerequiring a single action.

The cavity maintaining tool 60 having the foregoing structure is, alongthe groove 30a of the tissue protective tool 30, inserted into thecavity formed by the cavity forming tool 50 through the skin cut portionE1. At this time, the cavity maintaining tool 60 can smoothly beinserted into the cavity because the cavity formed by the cavity formingtool 50 is larger than the cross sectional area of the cavitymaintaining tool 60 and the insertion helper 61 is tapered forwards. Thecavity maintaining tool 60 is inserted until the insertion helper 61 ofthe cavity maintaining tool 60 projects through the skin cut portion E2.After the insertion helper 61 has projected through the skin cut portionE2, the insertion helper 61 is removed from the body 62.

FIG. 14A shows a state where the cavity maintaining tool 60 has beeninserted and retained in the cavity. In the foregoing state where thecavity maintaining tool 60 is retained in the cavity, the tissueprotective tool 30 is slowly pulled out through the skin cut portion E1.The foregoing state is shown in FIG. 14B. In the state shown in FIG.14B, the two ends of the cavity maintaining tool 60 project through theskin cut portion E1 and skin cut portion E2. Thus, the cavity G ismaintained just above the blood vessel C, which is the saphenous vein.

In the state shown in FIG. 14B, the hard endoscope 20 is inserted intothe cavity G through the opening 62b of the rear bases 62c of the cavitymaintaining tool 60, as shown in FIGS. 15A and 15B. An endoscope TVcamera 99a is connected to the hard endoscope 20 so that an image pickedup by the hard endoscope 20 is displayed on a monitor 99b. As a result,the operator is enabled to easily observe the overall region to betreated by sliding the hard endoscope 20. On the other hand, a treatmenttool, for example, forceps 91 are inserted into the cavity G through thehorizontal openings 62h formed on either side of the cavity maintainingtool 60. Moreover, for example, a hook probe 92 is inserted into thecavity G through the horizontal openings 62h formed on another sidesurface of the cavity maintaining tool 60.

As described above, the cavity maintaining tool 60 enables the hardendoscope 20, the forceps 91 and the hook probe 92 to be simultaneouslyinserted through the rear end of the cavity maintaining tool 60.Therefore, the operator is enabled to dissect the connective tissue 300on the blood vessel C from the blood vessel C by the hook probe 92 andcut the connective tissue 300 on the blood vessel C with the forceps 91to separate the connective tissue 300 on the blood vessel C from theblood vessel C while observing the cavity G with the hard endoscope 20.The states of the excising operation and the cutting operations areshown in FIGS. 16 to 19B. FIG. 16 shows an image in the cavity G pickedup by the hard endoscope 20. As shown in FIG. 16, the shafts 62e,horizontal openings 62h and bases 62c of the cavity maintaining tool 60,the blood vessel C and the branch F extending into the lateral directioncan be observed. FIG. 17 shows a state where a clip 96 is deformed by aclip applier 95 inserted into the cavity G through the horizontalopening 62h and serving as a treatment tool and an intermediate portionof the branch F is held by the clip 96. FIG. 18 shows a state justbefore an intermediate portion of the branch F between the two clips 96is cut by the forceps and a state after the same has been cut. Theforegoing operations are performed in a portion from the skin cutportion E1 to the skin cut portion E2. After the blood vessel C has beencompletely separated from the surrounding tissue as a result of theforegoing operation, the blood vessel C is cut at the positions of theskin cut portion E1 and skin cut portion E2 so as to be evulsed from theinside portion of the cavity G. As a result, evulsion of the bloodvessel C having a length of, for example, about 25 cm is completed.

If a longer blood vessel is required to be evulsed, a similar operationis performed through the skin cut portion E2 toward the knee. Thus,blood vessel C having a length of 50 cm to 60 cm extending from the skincut portion E2 toward the inguinal region and the ankle can be evulsedat a time.

FIGS. 19A and 19B show images picked up by the hard endoscope 20 toillustrate the states where the hook probe 92 is used. FIG. 19A shows astate where the hook probe 92 has been inserted through a right-handportion of the horizontal openings 62h of the cavity maintaining tool 60and approached from the right portion by a first hook 92a of the hookprobe 92. FIG. 19B shows a state where the hook probe 92 has beeninserted through a left-hand portion of the horizontal openings 62h ofthe cavity maintaining tool 60 and approached from the left portion by asecond hook 92a of the hook probe 92. Both of FIGS. 19A and 19B show thestate where intermediate portions of the blood vessel C are hooked bythe first and second hooks 92a and 92b and, thus, the blood vessel C hasbeen raised. In the foregoing operation, the connective tissue 300 onthe blood vessel C is cut by the forceps while being dissected from theblood vessel C so as to be separated from the blood vessel C by cutting.In the foregoing operation, the hard endoscope 20 is placedsubstantially on the upper surface of the cavity maintaining tool 60 sothat each treatment tool is inserted through the right and lefthorizontal openings 62h with respect to the hard endoscope 20. If thehook probe 92 is, in this case, used to dissect the blood vessel C, theinsertion operation can smoothly be performed by causing the right handto hold the hook probe 92 to insert the hook probe 92 through the righthorizontal openings 62h in the case where the operator is a right-handedperson. In this case, the second hook 92b warped to the right does nothinder the visual field of the hard endoscope 20, thus resulting in asatisfactory effect. If another treatment tool is used, it is preferablethat the left hand has the hook probe 92 and the right hand has thetreatment tool. In this case, use of the second hook 92c warped to theleft results in a satisfactory effect being obtained because the visualfield of the hard endoscope 20 is not hindered.

As described above, according to the first embodiment, the blood vesselcan be evulsed while protecting the blood vessel from being damaged andwithout a necessity of greatly incising the skin. Thus, a risk of acomplication occurring after the operation can be eliminated and asatisfactory advantage can be realized in terms of improving cosmeticeffect.

Among conventional methods of extracting a blood vessel, a method isavailable which is adaptable to extracting the subcutaneous bloodvessel, such as the saphenous vein in the lower extremity, and whichcomprises the steps of incising the skin along the blood vessel belowthe skin by using a knife or the like; further incising the panniculusadiposus and the connective tissue on the blood vessel which is thelower layers of the skin to expose the blood vessel having a lengthintended to be extracted; and cutting the two ends of the exposed bloodvessel to extract the same to the outside of the body.

However, since the extracting method of the foregoing type inevitablygreatly incises the skin, a too long time is required for the patient tobe cured. What is worse, the incised portion is scarred and hardened,thus causing a problem to arise in that the patient has a cramp in theleg when moves the leg and thus the patient feels a pain.

Accordingly, an attempt has been, as disclosed in Japanese PatentPublication No. 4-10328, made such that a portion of the skin is cut bya knife or the like; an endoscope guide tube is inserted into thesubcutaneous tissue; and the treatment is performed while observing thesubject portion with the endoscope.

When treatment is performed while observing the subject portion with theendoscope, the hook probe 92 according to the foregoing embodiment issuitable to perform the operation. Hitherto, a hook-type probe having astructure as disclosed in U.S. Pat. No. 5,318,582, U.S. Pat. No.5,346,503 and U.S. Pat. No. 5,356,419 has been employed. The hook typeprobe has a hook disposed at an end of a shaft thereof, and a handle isprovided for another end of the shaft. Thus, tissue can be hooked by thehook at the leading end of the shaft by the operator who holds thehandle to remove the tissue and a portion of the tissue can be removedby cutting.

However, the conventional hook-type prove has been arranged toselectively use a variety of probes which are different from one anotherin only the shapes of the hooks to be attached to the end of the shaftto be adaptable to the situation. Therefore, the probes are required tobe sent and received to and from the operator whenever the state of theportion to be treated is changed, thus resulting in a long time beingrequired to complete the operation.

In an example case where the blood vessel is dissected from thesurrounding tissue, a method has been generally employed in whichholding forceps are used to pick up the surrounding tissue so as to becut by cutting forceps. However, the foregoing method requires acomplicated operation and results in a long time being required tocomplete the operation.

Accordingly, a hook probe will now be described with which theoperations for passing the tool can be decreased and the time requiredto complete the operation can be shortened.

FIGS. 20 to 22B show a first example of the hook probe. As shown inFIGS. 20 and 21, a hook probe 130 has an operation portion 131. Theoperation portion 131 has an internal cavity 132 opened in the leadingend portion of the operation portion 131. A shaft 133 is disposed in thecentral portion of the internal cavity 132, the shaft 133 having thebase secured to the operation portion 131 and a leading end whichprojects forwards over the internal cavity 132. A pipe 134 capable ofmoving the axial direction is connected to the shaft 133. The shaft 133has the leading end to which the first hook 135 is secured, while asecond hook 136 is secured to the leading end of the pipe 134. The firstand second hooks 135 and 136 basically have the same shape each of whichwarped into a C-shape to project toward the side portions of the shaft133 and the pipe 134. A fixing member 137 disposed in the internalcavity 132 of the operation portion 131 is attached to the base portionof the pipe 134. A pin 193 penetrating an elongated hole 138, formed inthe operation portion 131, projecting outwardly is disposed on thefixing member 137. A operation button 140 is provided for the leadingend of the pin 139. Therefore, when the operator move forwards andrearwards the operation button 140 while holding the operation portion131, the pipe 134 is moved forwards or rearwards so that the first andsecond hooks 135 and 136 are opened and closed.

As can be understood from the images shown in FIGS. 22A and 22B andpicked up by the hard endoscope 20, the opening/closing type hook probe130 is inserted into the cavity G in a state where the first and secondhooks 135 and 136 are closed to approach the connective tissue 300 onthe blood vessel C. Then, the first and second hooks 135 and 136 areintroduced into the portion below the blood vessel C, followed byopening the first and second hooks 135 and 136. Thus, the hook probe 130is able to tear the connective tissue 300 on the blood vessel C so as toexpose the blood vessel C.

As described above, the hook probe 130 enables the operation forexcising the blood vessel from the surrounding tissue to be performed ina short time without using a plurality of treatment tools by using onlythe opening/closing hook probe 130. Although the first example has thestructure such that the first hook 135 is fixed and the second hook 136is made to be movable, a contrary structure may be employed. A structuremay be employed in which both of the first and second hooks 135 and 136are movable. If the outer edges of the first and second hooks 135 and136 are sharpened, the tissue can easily be cut and opened by the firstand second hooks 135 and 136 when the first and second hooks 135 and 136have been moved into a direction in which they are moved apart from eachother (see FIG. 22B).

FIGS. 23A and 23B show a second example of the hook probe. As shown inFIG. 23A, the opening/closing type hook probe 141 according to thisexample is composed of an operation portion 142, a shaft portion 143provided for the operation portion 142 and a hook portion 144 formed atthe leading end of the shaft portion 143. The operation portion 142comprises a cylindrical member 147. The cylindrical member 147 has, atthe leading end thereof, an opened portion 145 and, at a trailing endthereof, a closed portion 146. The cylindrical member 147 has a sidewall in which an elongated hole 148 is formed, the elongated hole 148being formed in the direction of the longitudinal axis of thecylindrical member 147. The closed portion 146 has a male thread portion149 on the outer surface thereof and, the closed portion 146 furthercomprising a female thread portion 150 formed in the axial centerportion thereof. A fixing member 152 having a slot 151 is screwed in thefemale thread portion 150. The outer surface of the base portion of thefixing member 152 is tapered. The fixing member 152 has a hole in thecentral portion thereof, the hole penetrating the fixing member 152 inthe axial direction of the same. The diameter of the hole is reduced atthe base end portion of the tapered fixing member 152 so that a steppedportion 153 is formed.

A cap 154 is screwed into the male thread portion 149 of the closedportion 146. A tapered hole 155, to which the base portion of the fixingmember 152 is received, is formed in the inner portion of the cap 154. Aslider 156 having a through hole 156a formed in the axial directionthereof is inserted into the cylindrical member 147 so as to be movablein the axial direction of the cylindrical member 147. The slider 156 issecured to an operation button 157 which is able to slide in the axialdirection of the cylindrical member 147 while being guided by theelongated hole 148. The cylindrical member 147 includes a coil spring158 at a position between the slider 156 and the closed portion 146. Theurging force of the coil spring 158 urges the slider 156 toward theleading end of the cylindrical member 147.

The shaft portion 143 comprises a shaft 160 and a pipe 161 attached onthe outside of the shaft 160 so as to be slidable in the axial directionthereof. The shaft 160 has the base portion which penetrates a throughhole 156a of the slider 156 and which is secured to the fixing member152. The base portion of the pipe 161 is secured to the slider 156.Therefore, when the slider 156 is longitudinal moved, the pipe 161 ismoved forwards or rearwards.

The hook portion 144 consists of a first hook 162 and a second hook 163.The base portion of the first hook 162 is secured to the leading end ofthe shaft 160. The base portion of the second hook 163 is secured to thebase portion of the pipe 161. As shown in FIG. 23B, the first hook 162is formed into a semi-circular arc shape and has a sharp portion 162ahaving a sharp leading end. Similarly to the fixing member 152, thestepped portion 153 is formed into a semi-circular arc shape and havinga sharp portion 163a having a sharp leading end. The first and secondhooks 162 and 163 are projection and pit portions 164 at the baseportions thereof so as to be engaged mutually.

As a result of the foregoing structure, when the operator touches theoperation button 157 of the operation portion 142 with the finger torearwards move the operation button 157 against the urging force of thecoil spring 158 as indicated by an alternate long and two short dashesline, the slider 156 is pulled into the inner portion of the cylindricalmember 147. When the rearward movement of the slider 156, the secondhook 163 is moved rearwards and apart from the first hook 162. As aresult, the hook portion 144 is opened. When the operator releases thefinger in the foregoing state, the slider 156 is moved forwards due tothe urging force of the coil spring 158 so that the second hook 163 isbrought into contact with the first hook 162 through the pipe 161.

As described above, the hook probe 141 according to this example isinitially inserted into the cavity G in the state where the first andsecond hooks 162 and 163 are opened to be allowed to approach theconnective tissue 300 on the blood vessel C. Then, with the hook probe130, the first and second hooks 135 and 136 are introduced into theportion below the blood vessel C, followed by opening the first andsecond hooks 135 and 136 so that the connective tissue 300 on the bloodvessel C is torn.

As described above, the hook probe 141 enables the operation forexcising the blood vessel from the surrounding tissue to be performed ina short time without using a plurality of treatment tools by using onlythe opening/closing hook probe 141. Although the second example has thestructure such that the first hook 162 is fixed and the second hook 163is made to be movable, a contrary structure may be employed. A structuremay be employed in which both of the first and second hooks 162 and 163are movable. If the outer edges of the first and second hooks 162 and163 are sharpened, the tissue can easily be cut and opened by the firstand second hooks 162 and 163 when the first and second hooks 162 and 163have been moved into a direction in which they are moved apart from eachother.

The opening/closing type hook probe 141 according to this example can beassembled by a user. The assembling operation is performed such that theshaft 160 having the first hook 162 is, from the position adjacent tothe second hook 163, inserted into the pipe 161 having the second hook163. Then, the shaft 160 and the pipe 161 are inserted into theoperation portion 142 in a state where the projection and pit portions164 of the first and second hooks 162 and 163 are aligned to each other.At this time, the coil spring 158 is held between the slider 156 and theclosed portion 146, and the shaft portion of the operation button 157 isguided by the elongated hole 148. Then, the base portion of the shaft160 is allowed to abut against the stepped portion 153 of the fixingmember 152. Then, the cap 154 is screwed in the male thread portion 149of the cylindrical member 147 so that the tapered hole 155 is allowed toabut against the tapered portion of the base portion of the fixingmember 152 so that the shaft 160 is clamped and secured.

Since the opening/closing type hook probe 141 can be decomposed asdescribed above, the hook probe 141 can easily be decomposed so as to bewashed. Since the projection and pit portions 164 are provided for thefirst and second hooks 162 and 163 and the abutting stepped portion 153is provided for the fixing member 152 of the shaft 160, the assemblingoperation can be performed in the state where the leading ends of thefirst and second hooks 162 and 163 are aligned to each other. Therefore,the assembling operation can be facilitated. Since the coil spring 158is attached, the hook portion 144 is closed in a usual state. Thus, thetissue of the organism can be protected from being damaged intentionallyby a sharp portion of the nail and the treatment can be performedsafely.

FIGS. 24A and 24B show a third example of the hook probe. A hook probe170 according to this example has the basic structure which is the sameas that according to the second example. However, a difference lies fromthe second example in the coil spring 158 being omitted. As a result ofthe foregoing structure, no load acts when the hook portion 144 isopened and closed. Thus, the operator is enabled to delicatelyopen/close the hook portion 144. Since the parts to be exploded at thedecomposition can be decreased, the assembling operation and washingoperation can easily be performed.

FIGS. 25A and 25B show a first modification of the excising member 10shown in FIGS. 4A to 4G. The same elements as those of the excisingmember 10 are given the same reference numerals and they are omittedfrom description. As shown in FIGS. 25A and 25B, the excising member 10'according to this modification has, at the leading end 12 thereof, anopening 180 permitting observation to be performed with the hardendoscope 20. FIG. 26A shows a state where the excising member 10', towhich the hard endoscope 20 has been attached, has been inserted belowthe skin through the skin cut portion E1. An image picked up by the hardendoscope 20 in the foregoing state of insertion is shown in FIG. 26B.

FIGS. 27A and 27B show a first modification of the tissue protectivetool 30 shown in FIG. 7A. As shown in FIG. 7A, a protective tool body31' of a tissue protective tool 30' according to this modification has across sectional shape as shown in FIG. 27B so that the groove 30a isformed by the outer surface of the protective tool body 31'. Since theresidual structures are the same as those of the tissue protective tool30, the same elements are given the same reference numerals and they areomitted from description.

FIGS. 28A to 28C show a second modification of the tissue protectivetool 30 and a first modification of the cavity forming tool 50. A tissueprotective tool 190 according to this modification comprises aprotective tool body 190a, which is a plate-like elongated member so asto be inserted into the subcutaneous tissue; and a flange portion 190bprojecting at the base portion of the protective tool body 190a in thewidthwise direction. Elongated grooves 191 are formed in the right andleft side surfaces of the protective tool body 190a, the elongatedgrooves 191 being formed in the lengthwise direction of the protectivetool body 190a (see FIG. 28C). A connection hole 31a is formed in theleading end portion of the protective tool body 190a, the connectionhole 31a being arranged to be caught by the slit 13a of the excisingmember 10 shown in FIGS. 4A to 4G so as to be detachably connected. Theprotective tool body 190a has a width capable of covering and protectingthe subcutaneous blood vessel to be protected and a length which issomewhat longer than the distance between the skin cut portion E1 andthe skin cut portion E2. The flange portion 190b projects to have awidth with which the insertion into the subcutaneous tissue through theskin cut portion E1 is inhibited. In order to smoothly insert the tissueprotective tool 190 into the subcutaneous tissue, the leading end of thetissue protective tool 190 is tapered in the forward direction. In orderto protect the tissue from being damaged, the leading end portion of thetissue protective tool 190 is formed into a smooth and moderate shape.On the other hand, to enable the cavity forming tool 50' to be guidedalong the tissue protective tool 30 when the cavity forming tool 50' isinserted into the subcutaneous tissue, engaging groove 192 capable ofengaging to the elongated grooves 191 of the tissue protective tool 190is formed in the lower surface of the cavity forming tool 50' (see FIG.28B). The connection hole 51 to be engaged to the hook 40b of thedilator hook 101 shown in FIG. 10A is formed in the leading end of thecavity forming tool 50'.

As a result of the foregoing structure, the engagement between theelongated grooves 191 and the engaging groove 192 permits the cavityforming tool 50' to be relatively moved with respect to the tissueprotective tool 30 in the engaged state so that the cavity forming tool50' is reliably guided by the tissue protective tool 30.

FIGS. 29, 30A and 30B show a first modification of the cavitymaintaining tool. As shown in FIGS. 29, 30A and 30B, a cavitymaintaining tool 201 has a body 202 formed into a semicircular(cylindrical) shape or circular arc shape obtainable by verticallycutting a cylinder into two sections, the body 202 being made of asynthetic resin or stainless steel. The body 202 has, at the two ends inthe lengthwise direction, openings 203. A side wall portion 204 of thebody 202 has two ends in each of which a lateral hole 205 elongated inthe lengthwise direction of the body 202 is formed. The right and leftlateral hole 205 is formed symmetrically with respect to thelongitudinal axis of the body 202. Moreover, the endoscope guide tube206 is, together with the body 202, provided for each of the two ends ofthe body 202. Each of the endoscope guide tube 206 is disposed on astraight line running parallel to the longitudinal axis of the body 202.The portion between the endoscope guide tube 206 are disconnected.

The upper semicircular portion of the cylindrical portion of each of theendoscope guide tubes 206 projects over the side wall portion 204 of thebody 202, while the lower semicircular portion projects over the lowerportion of the inner portion of the side wall portion 204. By disposingthe endoscope guide tube 206 at an intermediate position of the sidewall portion 204, in particular, by disposing the same in the centralportion, a largest possible hollow portion 207 is maintained in thecavity maintaining tool 201 while preventing excessive projection in theoutward direction. The two end surfaces and the lower surface of thebody 202 and the inner surface of the lateral hole 205 are rounded so asto protect the tissue in the body cavity from being damaged.

FIGS. 31A and 31B show a case where the cavity maintaining tool 201 isused in an extracting operation in which the same is retained in thesubcutaneous tissue to extract the subcutaneous blood vessel, such asthe saphenous vein. As a previous operation when the cavity maintainingtool 201 is retained, a space for retaining the cavity maintaining tool201 is formed in the subcutaneous tissue, for example, as shown in FIG.32.

Referring to FIG. 32, reference numeral 100 represents the skin, 200represents the subcutaneous tissue, such as the fat in the lower layerof the skin 100, 300 represents the connective tissue on the bloodvessel in the lower layer of the subcutaneous tissue 200, and Crepresents the blood vessel, such as the saphenous vein. FIG. 32 shows astate where a portion of the skin 100 is cut by a knife, thesubcutaneous tissue 200 and the connective tissue 300 on the bloodvessel C are cut, the excising member 10 is inserted through the skincut portion E1, and the retaining space 215 is formed in the body by theexcising member 10 while observing the subject portion with the hardendoscope 20.

After the retaining space 215 has been formed in the body, the body 202of the cavity maintaining tool 201 is inserted through the skin cutportion E1, as shown in FIGS. 31A and 31B. In a state where the outerend opening 203 is exposed to the outside of the body, the cavitymaintaining tool 201 is retained so that a cavity 216 is maintainedbelow the subcutaneous tissue 200 by the hollow portion 207. Then, aninsertion portion 218 of a hard endoscope 217 is inserted into either ofthe endoscope guide tubes 206 of the body 202, and the leading end ofthe insertion portion 218 is inserted into the cavity 216. A treatmenttool, for example, cutting forceps 219, is inserted from an end of thebody 202 through a lateral hole 205 to insert a forceps portion 219ainto the cavity 216. Moreover, a treatment tool, for example, a hookprobe 220, is inserted through either of the openings 203 of the body202, to insert a hook portion 220a into the cavity 216.

As described above, the hard endoscope 217, the cutting forceps 219 andthe hook probe 220 can simultaneously be inserted into either end of thebody 202 of the cavity maintaining tool 201. Moreover, while observingthe cavity 216 with the hard endoscope 217, the connective tissue 300 onthe blood vessel C can be separated from the blood vessel C and theconnective tissue 300 on the blood vessel C can be cut by the cuttingforceps 219 so as to separate the connective tissue 300 on the bloodvessel C from the blood vessel C.

FIG. 33 shows an image of the inside portion of the cavity 216 picked upby the hard endoscope 217 to be displayed on a monitor 217a. As shown inFIG. 33, the inner wall of the body 202, the opening 203 and the lateralhole 205 of the cavity maintaining tool 201, the connective tissue 300on the blood vessel C, the blood vessel C and the branch F extendingfrom an intermediate position of the blood vessel C into the horizontaldirection can easily be observed. FIG. 34 shows a state where thecutting forceps 219 has been inserted into the guide groove 222 of thescissors guide 221 to cause the cutting forceps 219 to slide in theguide groove 222 so that the cutting forceps 219 is enabled to easilyapproach the connective tissue 300 on the blood vessel C. FIG. 35 showsa state immediately before the connective tissue 300 on the blood vesselC is cut by the cutting forceps 219. FIG. 36 shows a state where theconnective tissue 300 on the blood vessel C has been cut by the cuttingforceps 219 and, thus, the blood vessel C and the branch F have beenexposed. FIG. 37 shows a state where a clip 224 is deformed by a clipprier 223, which is a treatment tool and an intermediate position of thebranch F is held. FIG. 38 shows a state immediately before anintermediate position of the branch F held by the two clips 224 is cutby the cutting forceps 219 and a state after the same has been cut. Asdescribed above, the cavity maintaining tool 201 can easily be used in avariety of states of usage.

FIG. 39 shows a second modification of the cavity maintaining tool. Thesame elements as those of the first modification are given the samereference numerals and they are omitted from detailed description. Acavity maintaining tool 225 according to this modification has a similarshape as that according to the first modification. A body 226 has asemicircular (cylindrical) shape or circular arc shape obtainable byvertically cutting a cylinder into two sections, the body 206 being madeof a synthetic resin or stainless steel. The body 206 has, at the twoends in the lengthwise direction, openings 227. The lower portions ofthe two ends of a side wall portion 228 of the body 226 have elongatedhorizontal holes 229 formed in the lengthwise direction of the body 226,the horizontal holes 229 being in the form of cut portions. The rightand left horizontal holes 229 are formed symmetrically with respect tothe lengthwise direction axial line of the body 226. Also the cavitymaintaining tool 225 can be used similar to the cavity maintaining tool201 according to the first modification.

FIGS. 40 and 41 show a third modification of the cavity maintainingtool. Note that the same elements as those of the first modification aregiven the same reference numerals and they are omitted fromillustration. The cavity maintaining tool 201 according to thismodification is used together with an insertion helper 230. Theinsertion helper 230 has a conical cylinder shape, only the lowerportion thereof is flattened or in the form obtainable by verticallycutting a conical cylinder and employing only the upper portion. Aleading end 231 of the insertion helper 230 is rounded to protect thetissue from being damaged. The base portion of the insertion helper 230has substantially same curvature radius as that of the body 202 of thecavity maintaining tool 201 so that no step is formed when connected.

A pair of connection members 232 positioned to correspond to the lateralhole 205 of the body 202 of the cavity maintaining tool 201, projectingrearwards and having elasticity are provided for the base portion of theinsertion helper 230. The leading end of the projecting portion of theconnection member 232 has an engaging projection 233 in the form of abent hook to be engaged to the leading end of the lateral hole 205 ofthe body 202 of the cavity maintaining tool 201.

When the insertion helper 230 having the foregoing structure is placedto face the end of the body 202 of the cavity maintaining tool 201 andthen the leading end of the projecting portion of each of the connectionmembers 232 is inserted into the body 202, the elasticity of theconnection members 232 causes the engaging projection 233 to be insertedinto the lateral hole 205 of the body 202. Thus, the insertion helper230 is connected to the body 202 by a single action. Therefore, when thecavity maintaining tool 201 is inserted into the retaining space 215 inthe subcutaneous tissue 200, the subcutaneous tissue 200 can be expandedby the tapered surface of the insertion helper 230 at the time ofinsertion. Thus, the cavity maintaining tool 201 can easily be inserted.

FIGS. 42A, 42B and 43 show a fourth modification of the cavitymaintaining tool. Note that the same elements as those of the first andthird modifications are given the same reference numerals and they areomitted from description. The cavity maintaining tool 201 according tothis modification is used together with the insertion helper 230. Athread hole 234 for connecting a traction member (not shown) is formedin a leading end 231 of the insertion helper 230. As shown in FIG. 43,the base portion of the insertion helper 230 has a diameter slightlylarger than that of the body 202 of the cavity maintaining tool 201. Thebase portion has a semicircular connection member 235 projectingrearwards. A connection pin 236 having a head portion 236a, the heightof which is the same or lower than the upper surface of the base portionof the insertion helper 230 is allowed to project over the upper surfaceof the connection member 235.

On the other hand, an engaging hole 237 to be engaged to the connectionpin 236 is formed in the upper surface of the body 202 of the cavitymaintaining tool 201. The engaging hole 237 is composed of alarge-diameter portion 237a to be freely engaged to the head portion236a of the connection pin 236 and a small-diameter portion 237b to beclosely engaged to the shaft portion of the connection pin 236, thelarge-diameter portion 237a and the small-diameter portion 237b beingformed continuously in the longitudinal direction. The large-diameterportion 237a is disposed in the rear of the small-diameter portion 237b.

The insertion helper 230 having the foregoing structure is located toface the end of the body 202 of the cavity maintaining tool 201, and theconnection member 235 is inserted into the opening 203 of the body 202.Then, the head portion 236a of the connection pin 236 is freely insertedinto the large-diameter portion 237a of the engaging hole 237. When theinsertion helper 230 is moved toward the leading end 231 in theforegoing state, the connection pin 236 is closed engaged to thesmall-diameter portion 237b of the engaging hole 237 so that theinsertion helper 230 is connected to the body 202 by a single action.

By using the insertion helper 230, when the cavity maintaining tool 201is inserted into the retaining space 215 of the subcutaneous tissue 200,it can be inserted while expanding the subcutaneous tissue 200 by thetapered surface of the insertion helper 230. As a result, the cavitymaintaining tool 201 can easily be inserted.

FIG. 44 shows a fifth modification of the cavity maintaining tool.Referring to FIG. 44, reference numeral 240 represents cavitymaintaining tool. The cavity maintaining tool 240 has a body 241 formedinto a cylindrical shape. The body 241 has the two ends each having anopening 242. An opening portion 243 in the form of a wide and elongatedhole is formed in the lower portion of the body 241 in the lengthwisedirection of the body 241. On the other hand, a pair of horizontal holes244 are formed in the peripheral wall in the upper portion of the body241, the horizontal holes 244 being formed in the lengthwise directionof the body 241. Also the cavity maintaining tool 240 can be usedsimilarly to the cavity maintaining tool according to the foregoingmodifications.

FIGS. 45A and 45B show a sixth modification of the cavity maintainingtool. Referring to FIGS. 45A and 45B, reference numeral 245 represents acavity maintaining tool. A body 246 of the cavity maintaining tool 245is formed into a flat cylindrical shape having two ends in whichopenings 247 are formed. An opening portion 248 in the form of a wideelongated hole is formed in the lower portion of the body 246, theopening portion 248 being formed in the lengthwise direction of the body246. Also the cavity maintaining tool 245 can be used similarly to thecavity maintaining tool according to each of the foregoingmodifications.

FIGS. 46A and 46B show a seventh modification of the cavity maintainingtool. Referring to FIGS. 46A and 46B, reference numeral 250 represents acavity maintaining tool. A body 251 of the cavity maintaining tool 250is formed into a semicircular (cylindrical) shape which is the upperhalf of two sections formed by vertically cutting a cylinder. The body251 has an opening at each of the two ends thereof. Moreover, a cutportion 253 is formed in the upper wall at each of the two ends of thebody 251. The cut portion 253 expands the degree of opening of theopening 252 to enable a treatment tool 254 to easily be inserted andoperated. A pair of leg portions 255 formed by the cut portion 253extend outwards in the axial direction of the body 251 to press tissue256 so that a treatment tool 254 is easily inserted and operated.Reference numeral 257 represents an endoscope guide tube similar to thataccording to the foregoing modifications.

FIG. 47 shows an eighth modification of the cavity maintaining tool.Referring to FIG. 47, reference numeral 258 represents a cavitymaintaining tool. A body 259 of the cavity maintaining tool 258 isformed into a semicircular (cylindrical) shape which is the upper halfof two sections formed by vertically cutting a cylinder. The body 259has the two ends in which openings 260 are formed by expanding the outerwall of the body 259. The opening 260 has a satisfactorily large size toeasily insert and operate the treatment tool 254.

FIGS. 48A and 48B show a ninth modification of the cavity maintainingtool. Referring to FIGS. 48A and 48B, reference numeral 261 represents acavity maintaining tool. A body 262 of the cavity maintaining tool 261is formed into a semicircular (cylindrical) shape which is the upperhalf of two sections formed by vertically cutting a cylinder. Moreover,openings 263 are formed in the two ends of the body 262. Two horizontalholes 264 are formed on the two side walls of the body 262, thehorizontal holes 264 being formed in the lengthwise direction of thebody 262. The horizontal holes 264 are covered with a semicircular(cylindrical) cover 265 projecting toward the outside of the body 262.An end of the cover 265 is opened so that the horizontal hole 264 isopened, while another end is closed. Thus, a tapered shape is formedfrom the opened portion toward the closed portion to guide the treatmenttool 219. As shown in FIG. 48B, for example, the cutting forceps 219 canbe inserted through the horizontal hole 264 and the insertion portion218 of the hard endoscope 217 can be inserted into the endoscope guidetube 206. As a result, treatment can be performed while observing theinside portion of the cavity 216.

FIG. 49 shows a tenth modification of the cavity maintaining tool.Referring to FIG. 49, reference numeral 266 represents a cavitymaintaining tool. A body 267 of the cavity maintaining tool 266 isformed into a semi-cylindrical shape obtained by vertically cutting acylinder. Moreover, an opening 268 is formed in each of the two ends ofthe body 267. The opening 268 may be formed by opening the outer wall ofthe body 267. By inwardly deforming each of the two side walls at thetwo ends of the body 267 into a semicircular shape, a circular-arc guidegroove 269 is formed on the outer wall of each of the two side walls.Moreover, a horizontal hole 270 connected to the inner portion of thebody 267 is formed at an end of the guide groove 269. Therefore, atreatment tool (not shown) can be inserted into the body 267 through thehorizontal hole 270 while being guided by the guide groove 269.

FIGS. 50 to 54 show an eleventh modification of the cavity maintainingtool. A cavity maintaining tool 201 according to this modification isused together with an insertion helper 271. As shown in FIGS. 50, 51Aand 51B, a leading end portion 272 of the insertion helper 271 Has athread hole 273 to which a traction member (not shown) is connected.Moreover, a rectangular retainer plate 274, on which the hard endoscopebody 202 of the cavity maintaining tool 201 is placed, is fixed to thebase portion of the insertion helper 271. A raised and bent edge portion275 to be engaged to the lower edge of the body 202 of the cavitymaintaining tool 201 is formed in the peripheral portion of theretaining plate 274. Moreover, a connection pin 276 is formed to projectover the base portion of the insertion helper 271, the connection pin276 being arranged to be inserted into the endoscope guide tube 206 ofthe cavity maintaining tool 201.

With the insertion helper 271 having the foregoing structure, when theendoscope guide tube 206 of the cavity maintaining tool 201 is, as shownin FIG. 51B, inserted into the connection pin 276 and the cavitymaintaining tool 201 is placed on the retaining plate 274, the cavitymaintaining tool 201 can be connected to the insertion helper 271 with asingle action. When the cavity maintaining tool 201 is inserted into theretaining space 215 of the subcutaneous tissue 200, it can be insertedwhile expanding the subcutaneous tissue 200 by the tapered surface ofthe insertion helper 271. Thus, the insertion of the cavity maintainingtool 201 can be facilitated.

FIGS. 52 to 54 show an operation for inserting the cavity maintainingtool 201 into the retaining space 215 of the subcutaneous tissue 200 byusing the insertion helper 271 according to this modification. Referencenumeral 277 represents a lower extremity, and E1 and E2 represent skincut portions formed by cutting the skin 100 by a knife or the like. Aexpander 280, serving as a traction member, is connected to the threadhole 273 of the insertion helper 271. The expander 280 is composed of ashaft 281 and a flat expansion portion 282 formed at an end of the shaft281. Reference numeral 283 represents a protector previously set in theretaining space 215 of the subcutaneous tissue 200 in order to guide theinsertion helper 271 and the cavity maintaining tool 201.

The expansion portion 282 of the expander 280 is, as a leading end ofthe insertion operation, introduced into the retaining space 215 of thesubcutaneous tissue 200 through skin cut portion E1 which is one of theskin cut portions E1 and E2. On the other hand, the expansion portion282 is ejected through the other skin cut portion E2. In this state, theoperator holds the expansion portion 282 as a handle and pulls in adirection indicated by an arrow so that the expansion portion 282 isinserted while expanding the subcutaneous tissue 200 by the taperedsurface of the insertion helper 271. Then, the cavity maintaining tool201 is inserted into the retaining space 215 of the subcutaneous tissue200, and then the two ends of the cavity maintaining tool 201 areretained while being exposed through the skin cut portions E1 and E2.After the two ends have been exposed, the insertion helper 271 and thecavity maintaining tool 201 are separated from each other.

FIGS. 55, 56A and 56B show an example of a structure which is differentfrom the eleventh modification in a means for attaching/detaching thecavity maintaining tool 201 to and from the insertion helper 271. Thatis, when the operator holds the two side walls of the body 202 of thecavity maintaining tool 201 with fingers 284 to elastically and inwardsdeform the body 202 to suspend the engagement of the body 202 with theraised portion 275 of the insertion helper 271, followed by downwardspushing the retaining plate 274 of the insertion helper 271, theinsertion helper 271 and the cavity maintaining tool 201 can beseparated from each other.

FIGS. 57 to 59 show a twelfth modification of the cavity maintainingtool. FIG. 57 shows a state where forceps 285 for a surgical operationare inserted into the subcutaneous tissue 200 through the lateral hole205 of the cavity maintaining tool 201 retained in the subcutaneoustissue 200. The hard endoscope 217 is inserted through the opening 203,which is one of two openings of the cavity maintaining tool 201.Moreover, the skin 100 opposite to the lateral hole 205 of the cavitymaintaining tool 201 is cut by a knife or the like. The forceps 285 fora surgical operation are inserted into the cavity 216 through a formedskin cut portion 278. FIG. 58 shows an image of the inside portion ofthe cavity 216. The forceps 285 for a surgical operation, the inner wallof the body 202 of the cavity maintaining tool 201, the opening 203, thelateral hole 205, the connective tissue 300 on the blood vessel C, theblood vessel C and the branch F extending at an intermediate position ofthe blood vessel C toward a horizontal direction can be observed. FIG.59 shows a closed up image of a forceps portion 285a of the forceps 285for a surgical operation and the blood vessel C photographed by a squinttype hard endoscope. A clear image of detailed portions can be captured.

FIGS. 60A to 60C show a thirteenth modification of the cavitymaintaining tool. FIG. 60A shows a cavity maintaining tool 286 in anassembled state. The cavity maintaining tool 286 can be decomposed intoa plurality of members, as shown in FIGS. 60B and 60C. That is, thecavity maintaining tool 286 is composed of a cavity maintaining tool286, the body 288 and the handle portion 289 so that decomposition ofthe foregoing elements is enabled. The body 288 of the cavitymaintaining tool 286 has shafts 291 provided by a number suitable tomaintain the cavity; and an endoscope guide tube 292 for holding thescope. The shafts 291 and the endoscope guide tube 292 are arrangedbetween bases 290 disposed at the two longitudinal ends of the body 288.The shafts 291 and the endoscope guide tube 292 are formed into a framestructure running parallel to the axis direction of the body 288.

The bases 290 disposed at the two longitudinal ends of the body 288 arein the same arch shape and have an opening 293 for enabling thetreatment tool to be smoothly inserted. The endoscope guide tube 292 isarranged between the two bases 290 at a position on the rear of thecentral portion of the bases 290. The plural shafts 291 are arrangedbetween legs 294 of the bases 290. Since the shafts 291 and theendoscope guide tube 292 are formed in the frame shape running parallelto the axial direction of the body 288, a plurality of lateral holes 205are greatly opened in the side portion of the body 288, the lateralholes 205 being connected to the hollow portion 296 in the body 288.

A pin-type locating member 295 is formed to project over the front wallin the lower portion of each of the two leg portions 294 of the bases290, the locating member 295 being provided for position location withrespect to the insertion helper 287. The two end surfaces, the lowersurface and the side surfaces, which come in contact with the subjectsubcutaneous tissue, of the body 288 are rounded without any edge. Eachmember of the cavity maintaining tool 286 is made of a synthetic resinor stainless steel. The endoscope guide tube 292 of the body 288 has,similarly to that of the first modification, a hole portion 292a havingtwo ends which are opened in the longitudinal direction. Theintermediate portion of the endoscope guide tube 292 is opened in ahollow portion 296 in the body 288.

The handle portion 289 is made of a straight rod member having a baseportion on which a large-diameter handle portion 297. The handle portion289 has a securing male thread portion 298 at the leading end thereof.The handle portion 289 is inserted into the endoscope guide tube 292 ofthe body 288. The male thread portion 298 of the insertion helper 287 isscrewed in the female portion 299 formed in the rear end surface of theinsertion helper 287. Moreover, the body 288 is held and secured betweenthe rear end surface of the insertion helper 287 and the handle portion297. By removing the handle portion 289, the insertion helper 287, thebody 288 and the handle portion 289 can be decomposed.

The insertion helper 287 is formed into a semi-conical shape having arounded leading end. The surface of the lower end portion of theinsertion helper 287 is formed into a flat shape to form a hollowportion therein. A leading end 287a of the insertion helper 287 has aguide projection 287b. The guide projection 287b projects slightly overthe lower surface of the insertion helper 287. Thus, when the cavitymaintaining tool 286 is retained in the subject subcutaneous tissue, theguide projection 287b is received by a guide groove 301a of an elongatedtissue protector 301, which has been previously inserted. The leadingend 287a of the insertion helper 287 is, when combined with the tissueprotector 301, received in the guide groove 301a of the tissue protector301. The insertion helper 287 has, at the rear end thereof, a locatinghole 302 which receives the locating member 295 of the body 288. At theleading end of the tissue protector 301, a hooking hole 301b is formed.The tissue protector 301 has, at the rear end thereof, a flap 301cextending to the right and left.

The operation of the cavity maintaining tool 286 will now be described.As shown in FIG. 60A, the cavity maintaining tool 286 is fixedlyassembled as described above, such that the handle portion 289 isinserted into the endoscope guide tube 292 of the body 288, the malethread portion 298 of the handle portion 289 is screwed in the femaleportion 299 formed in the rear end surface of the insertion helper 287,and the body 288 is held between the rear end surface of the insertionhelper 287 and the handle portion 297. The tissue protector 301 forprotecting the subject tissue from being damaged is inserted througheither of cut portions previously formed for retaining the cavitymaintaining tool 286 to be apart from each other. The tissue protector301 is retained in the cavity such that it is pulled to be movedforwards from the forward cut portion by hooking hole 301b to the slit13a of the excising member 10 and pulling the excising member 10, asshown in FIG. 8A and FIG. 8B. The tissue protector 301 is retained justabove the blood vessel to be evulsed.

The guide projection 287b of the insertion helper 287 is received in theguide groove 301a of the tissue protector 301 as described above. Then,the tapered surface of the insertion helper 287 expands the subcutaneoustissue so that insertion is performed. Since the cavity maintaining tool286 has round portion on the side surface in the lengthwise directionwhich comes in contact with the subject tissue, the tissue in the bodycavity can be protected from being damaged. Since the leading end 287aof the insertion helper 287 is received in the guide groove 301a whencombined with the tissue protector 301, the relatively sharp leading end287a does not damage the subject tissue when the cavity maintaining tool286 is retained in the subject tissue. As a result insertion to theposition below the skin can easily be performed along the subjecttissue. After insertion has been performed, the insertion helper 287 istaken out through the front cut portion, while the tissue protector 301and the handle portion 289 are taken out through the rear cut portion soas to be removed from the body 288. Thus, the retained body 288 resultsin a satisfactorily large cavity to be maintained in the portion belowthe skin.

If a method in which the front cut portion is not formed is employed,the insertion helper 287 may be retained and the tissue protector 301 ispulled toward the operator so as to be removed. Since the body 288 is inthe form of the frame structure, the treatment tool can be insertedthrough the lateral holes 205 opened greatly simultaneously withinsertion of the endoscope through the leg portions 294 at the two endsthrough the endoscope guide tube 292. Thus, the operation can beperformed further easily as compared with the foregoing modifications.The cavity maintaining tool according to first to twelfth modificationsis formed into a cylindrical shape or the like having the lateral holes205 which opens the side portion. Although a satisfactory effect can beobtained, the thirteenth modification employing the frame structurepositively and greatly opens the lateral holes 205 of the body 288.Thus, the treatment tool can be operated further smoothly in the cavity.Since the frame structure is employed, the cavity can be maintainedwhile opening the lateral holes 205. Moreover, the strength of the body288 can be improved.

FIGS. 61A and 61B show a fourteenth modification of the cavitymaintaining tool. Note that the same elements as those of the thirteenthmodification are given the same reference numerals, and they are omittedfrom description. A cavity maintaining tool 310 is composed of theinsertion helper 287, the body 288 and the handle portion 289. Inparticular, the leg portions 294 of the bases 290 of the body 288 areprovided with a groove portion 311 and a hole portion 292a of theendoscope guide tube 292. The insertion helper 287, the body 288 and thehandle portion 289 of the cavity maintaining tool 310 are assembled andsecured similarly to the foregoing method. By inserting the body 288along the subject tissue and by removing the insertion helper 287 andthe handle portion 289, the body 288 is able to maintain a satisfactorylarge cavity. Since the body 288 has the frame structure, the treatmenttool can be inserted through the lateral holes 205 in the side surfacesimultaneously with the insertion of the endoscope through the holeportion 292a of the endoscope guide tube 292. Thus, the operation can beperformed further smoothly. Since the groove portion 311 is formed inthe base 290, the treatment tool can further smoothly be insertedthrough the groove portion 311.

FIGS. 62A to 62G show a fifteenth modification of the cavity maintainingtool. The same elements as those of the thirteenth modification aregiven the same reference numerals and they are omitted from thedescription. A cavity maintaining tool 320 is composed of the insertionhelper 287 and the body 288. Each of bases 321 formed in the front andrear portions of the body 288 is in the form of an H-shape having largegroove portions 322 in the right and left side portions, as shown inFIGS. 62A and 62B. The insertion helper 287 has a guide projection 287b.Moreover, an elastic member 323 serving as a connection member so as tobe engaged and secured to the body 288 is formed to project over therear end of the insertion helper 287. The elastic member 323 may be, forexample, an engaging claw as shown in FIG. 62C, an O-ring 323b as shownin FIG. 62D or a C-ring 323c as shown in FIG. 62E. The elastic member323 is inserted into a hole portion 292a in the front portion of theendoscope guide tube 292 of the body 288 so as to secure the insertionhelper 287 and the body 288.

The front hole portion 292a of the endoscope guide tube 292 is formedinto a cylindrical shape having no groove as shown in FIG. 62F orprovided with a groove 325 capable of satisfactorily receiving theprojection shape of the elastic member 323. The locating member 295 ofthe body 288 of the cavity maintaining tool 320 is received by andengaged to the locating hole 302 of the insertion helper 287 and theelastic member 323 of the insertion helper 287 is inserted into thefront hole portion 292a of the endoscope guide tube 292. Thus, the body288 and the insertion helper 287 can be assembled as shown in FIG. 62A.As a result, insertion to the position below the skin can be performedalong the subject tissue. Since the insertion helper 287 can easily beremoved from the body 288 by a single action, the body 288 is able tomaintain a satisfactorily large cavity under the skin. Since the framestructure is formed, when the endoscope has been inserted by theendoscope guide tube 292, the treatment tool can simultaneously beinserted. Thus, the operation can further smoothly be performed. Sincethe structure is different from the thirteenth modification such thatthe base is formed into the H-shape and the groove portion 322 isformed, the treatment tool can further smoothly be inserted.

FIGS. 63A and 63B show sixteenth modification of the cavity maintainingtool. The same elements as those of the thirteenth modification aregiven the same reference numerals and they are omitted from thedescription. A cavity maintaining tool 330 is composed of an insertionhelper 287, a body 288 and a handle portion 289. An air suction pipe 331is arranged between front and rear bases 332 of the body 288individually from the endoscope guide tube 292 and the shafts 291. Theair suction pipe 331 is disposed at a relatively upper position to runparallel to the endoscope guide tube 292 and the shafts 291 while beingapart from the same. The air suction pipe 331 has a multiplicity ofsuction holes 331a in the wall thereof. The front and rear bases 332have grooves 334. An opening 335 is formed on the inside of the base332.

An air suction tube 336 connected to the air suction pipe 331 isconnected to the base 332. The air suction tube 336 is detachablyconnected. The air suction tube 336 may be connected to the rear base332 or may be connected to either of the bases 332. Similarly to thethirteenth modification, the cavity maintaining tool 330 can beassembled such that the locating member 295 of the body 288 is receivedby the locating hole 302 of the insertion helper 287; and the handleportion 289 is used to connect and secure the insertion helper 287 andthe body 288 to each other. The cavity maintaining tool 330 can be usedsimilarly to the thirteenth modification. After it has been retained,air suction in the cavity can be performed through the air suction pipe331.

According to the sixteenth modification, insertion to the position belowthe skin along the subject tissue can be performed. By removing theinsertion helper 287 and the male thread portion 298, the body 288 isable to satisfactorily large cavity below the skin. Since the body 288has the frame structure, the treatment tool can be inserted through therear opening 335 of the body 288 and the lateral hole in the sidesurface simultaneously with insertion of the endoscope through theendoscope guide tube 292. Thus, the operation can further smoothly beperformed. Since the groove portion 334 is formed in the base 332, thetreatment tool can further smoothly be inserted. Since the air suctiontube 336 is connected to the air suction pipe 331, air in the cavity canbe sucked so that fogging of the visual field of the endoscope isprevented or overcome.

FIGS. 64A and 64B show a seventeenth modification of the cavitymaintaining tool. This modification has common elements as those of thethirteenth to sixteenth modifications. The same elements are given thesame reference numerals and they are omitted from the description. Acavity maintaining tool 340 is composed of the insertion helper 287having the elastic member 323 and the body 288. The handle portion 289is omitted in this modification. The shafts 291 of the body 288 alsoserves as the air suction pipe 331 so that the shafts 291 and the airsuction pipe 331 are not provided individually. Similarly to thethirteenth modification, each of the front and rear bases 321 is formedinto an H-shape to form the large groove portions 322 in the right andleft outer portions. Connection ports 342 individually connected to theair suction pipe 331 also serving as the shafts 291 are formed in thebases 321. A suction tube 341 is detachably connected to either of theconnection port 342. A portion or the overall portion of each airsuction pipe 331 may be connected in the base 321 to connect one suctiontube 341 to a plurality of the air suction pipes 331.

The cavity maintaining tool 340 is structured due to the followingsecuring operation. The locating member 295 of the body 288 determinesthe position of the insertion helper 287, and the elastic member 323,which is the connection member, is inserted into the opening holeportion 292a of the body 288 so that the insertion helper 287 and thebody 288 are engaged and secured to each other. Similarly to theforegoing modification, insertion along the subject tissue into aposition below the skin is performed so that the body 288 is retained inthe cavity. Air in the cavity can be sucked through the shafts 291 alsoserving as the air suction pipe 331 after the body 288 has beenretained. The insertion helper 287 can easily be removed from the body288 by a single action. Thus, the body 288 is able to maintain asatisfactorily large cavity below the skin. Since the body 288 has theframe structure, the treatment tool can be inserted through the lateralhole portion of the body 288 simultaneously with the insertion of theendoscope through the endoscope guide tube 292. Thus, the operation canfurther smoothly be performed. In a manner different from the thirteenthembodiment, each base 321 is formed into the H-shape to have the grooveportion 322 so that the treatment tool is further smoothly inserted. Byconnecting the suction tube 341 to either of the shafts 291 also servingas the air suction pipe 331, air in the cavity can be sucked to preventand overcome foregoing of the visual field of the endoscope.

FIGS. 65A and 65B show a first example of a guide member for protectingthe subcutaneous tissue while guiding the forceps 91 (219) according tothe first embodiment and the modifications. As shown in FIG. 65A, aguide member 440 according to this example is formed into an elongatedrod-like shape so as to be inserted into the subcutaneous tissue. Theguide member 440 has a body 440a having a width and length with which atleast a portion of the subcutaneous tissue to be protected is coveredand protected. An operation rod 440b having a diameter smaller than thatof the body 440a is connected to the base portion of the body 440a. Asshown in FIG. 65B, the body 440a of the guide member 440 has asubstantially flat cross sectional shape. A protective surface 442 ofthe body 440a which is brought into contact with the subcutaneous tissueto be protected has an accommodation groove 447 for accommodating andprotecting the subcutaneous tissue, the accommodation groove 447 beingformed for the overall length of the protective surface 442. A guidesurface 444 opposite to the protective surface 442 has a guide groove446 for guiding the treatment tool, the guide groove 446 being formed inthe lengthwise direction of the guide surface 444. The two ends of theguide groove 446 are closed by walls. In particular, a groove wall 430adjacent to the leading end restrict projection of the treatment tooltoward the leading end, the treatment tool being guided along the guidegroove 446. The guide groove 446 may be formed for the overall length ofthe body 440a. To easily insert the body 440a into the subcutaneoustissue and to easily separate the subcutaneous tissue, to be protected,from other subcutaneous tissue, the leading end of the body 440a istapered in the forward direction. To protect the tissue from beingdamaged, the leading end portion of the body 440a is formed into asmooth and moderate shape.

A case where an operation for extracting the saphenous vein by using theguide member 440 having the foregoing structure with the endoscope willnow be described with reference to FIGS. 66A to 68B. Initially, anoperation similar to the first embodiment and modifications is performedso that a cavity having a predetermined size is formed above thesaphenous vein C. The cavity is maintained by the doom type cavitymaintaining tool 201 shown in FIG. 29. The foregoing state is shown inFIG. 66A. In the space maintained by the cavity maintaining tool 201,the saphenous vein C is exposed while being partially covered by theconnective tissue 300 on the blood vessel C. The reason for this is thatthe excising member 10 sometimes passes through the connective tissue300 on the blood vessel C when the excising operation using the excisingmember 10 is performed. Note that symbol F represents a branch from thesaphenous vein C.

In the foregoing state, an operation for excising the connective tissue300 on the blood vessel C, which is a membrane tissue, from thesaphenous vein C is required. Accordingly, the guide member 440 isintroduced into the space maintained by the cavity maintaining tool 201through the skin cut portion E1. Then, the guide member 440 is pushedforwards toward a space between the connective tissue 300 on the bloodvessel C, which has not been dissected, and the saphenous vein C, asindicated by an arrow (see FIG. 66B). Note that the foregoing operationis performed through the endoscope (not shown) which has been introducedinto the cavity maintaining tool 201. As shown in FIG. 67A, the guidemember 440 is inserted between the connective tissue 300 on the bloodvessel C, which has not been dissected, and the saphenous vein C so thatthe connective tissue 300 on the blood vessel C and the saphenous vein Care dissected from each other. At this time, the guide member 440 isinserted to cause the saphenous vein C to be placed along theaccommodation groove 447. FIG. 67B shows the vertical cross sectionrealized in the foregoing state. FIG. 67C shows a horizontal crosssection. At this time, the blade of the forceps 91 (219) is insertedalong the guide groove 446.

After the tissue C and 300 have been dissected to a certain extent bythe guide member 440, the blades of the forceps 91 (219) are movedforwards along the guide groove 446 so as to place the connective tissue300 on the blood vessel C between the upper blade and the lower blade,as shown in FIGS. 68A and 68B. In the foregoing state, the connectivetissue 300 on the blood vessel C is cut. The foregoing operation isrepeated until the overall body of the saphenous vein C is exposed.

FIGS. 69A to 69C show a second example of the guide member forprotecting the subcutaneous tissue while guiding the forceps 91 (219). Aguide member 450 according to this example is formed into an elongatedtubular member. As illustrated, the guide member 450 has a hole 452 intowhich an insertion portion 455a of the endoscope 455 can be inserted.The leading end of the hole 452 is closed, while the base portion of thehole 452 is opened. The guide member 450 is fully made of transparentmaterial to permit observation with the endoscope 455 inserted into thehole 452. The guide member 450 has a guide groove 451 capable of guidinga treatment tool or the like, the guide groove 451 being formed for theoverall length of the guide member 450. The leading end of the guidemember 450 is tapered in the forward direction to be easily insertedinto the subcutaneous tissue and to easily dissect the subcutaneoustissue, to be protected, from the other subcutaneous tissue. To protectthe tissue from being damaged, the leading portion of the guide member450 is formed into a smooth and moderate shape.

The guide member 450 having the foregoing structure enables treatment tobe performed in such a manner that the insertion portion 455a of theendoscope 455 is inserted into the hole 452 through the opening in thebase portion to observe the portion to be treated. For example, whileguiding the forceps along the guide groove 451 and performing treatment,the state can be observed through the endoscope 455. Since the guidemember 450 prevent contact between the treatment tool and thesubcutaneous tissue to be protected, that is, the guide member 450protects the subcutaneous tissue positioned below the guide member 450,the subcutaneous tissue can be protected from being damaged during theoperation, such as the excising operation.

FIGS. 70 to 72B show a third example of the guide member for protectingthe subcutaneous tissue while guiding the forceps 91 (219). As shown inFIG. 70, a guide member 460 according to this example is formed into anelongated tubular member. As illustrated, the guide member 460 has ahole 462 into which a treatment tool 465, such as forceps, can beinserted. The leading end of the hole 462 is closed, while the baseportion of the hole 462 is opened. The opening 461 has a size with whichinterference with, for example, interference of the movement of aforceps portion 466 of the treatment tool 465 is prevented. The leadingend of the guide member 460 is tapered in the forward direction to beeasily inserted into the subcutaneous tissue and to easily dissect thesubcutaneous tissue, to be protected, from the other subcutaneoustissue. To protect the tissue from being damaged, the leading portion ofthe guide member 460 is formed into a smooth and moderate shape.

When the guide member 460 having the foregoing structure is used, forexample, the treatment tool 465 is inserted into the hole 462 throughthe opening in the base portion of the guide member 460 so that theforceps portion 466 is placed in the opening 461, as shown in FIGS. 71Ato 71C. As shown in FIGS. 72A and 72B, the guide member 460 is insertedbetween, for example, the saphenous vein C and the connective tissue 300on the blood vessel C to perform excision in a state where a pair ofblades 466a and 466b are opened. After the excision has been performedto a certain extent, the connective tissue 300 on the blood vessel C iscut by the blades 466a and 466b. As described above, the guide member460 according to the third example has the arrangement such that thetreatment tool 465 is accommodated in the hole 462 and only the forcepsportion 466 directly relating to the treatment is exposed through theopening 461. Therefore, contact between the tissue, to be protected, andthe treatment tool 465 can reliably be prevented as compared with thecase where the treatment tool is guided along the guide groove.

FIGS. 73 and 74 show a second modification of the excising member. Theexcising member according to the second modification has the functionsof the excising member 10 and the cavity forming tool 50 according tothe first embodiment. As shown in FIG. 73, an excising member 500according to this modification has a pipe member 514, which is aninsertion portion, a leading end 526 formed at the leading end of thepipe member 514 and made of a transparent resin material and a rear endmember 522 formed at the base portion of the pipe member 514. A balloon516 is attached to the pipe member 514 to cover the overall length ofthe pipe member 514. The balloon 516 has securing regions 518 formed atthe leading end and the trailing end thereof with which the balloon 516is closed secured to the pipe member 514. Note that the other portionsof the balloon 516 are not secured to the pipe member 514. An outersheath 512 is attached on the outside of the balloon 516 to bedetachable with respect to the excising member 500. As a result, theballoon 516 is, in a contracted state, accommodated in the outer sheath512. The outer diameter of the outer sheath 512 is made to be smallerthan that of the leading end 526 of the excising member 500. The baseportion of the outer sheath 512 is screwed in the thread portion 520 ofthe rear end member 522 in such a manner that the outer sheath 512covers from the rear end portion of the excising member 500 so that theouter sheath 512 is attached and secured to the excising member 500. Inthe foregoing case, the leading end of the outer sheath 512 is engagedto a rear end portion 526a of the leading end 526 having an outerdiameter somewhat smaller than the inner diameter of the outer sheath512.

As the material of the balloon 516, an extension material, such assilicon rubber and latex, for use as a balloon for an endoscope; or anon-extension material, such as polyethylene terephthalate, polyamide orolefin plastic, for use as a balloon dilator. In the foregoing case, theballoon 516 is previously formed into a required shape and folded andaccommodated in the outer sheath 512.

The pipe member 514 of the excising member 500 is provided with one ormore communication holes 510 communicated with the inside portion of theballoon 516. The rear end member 522 of the excising member 500 has,similarly to the excising member 10 shown in FIGS. 4A and 4B, an L-shapeslit 13a capable of hooking the tissue protective tool 30 shown in FIG.7A and a rotation-stopping groove 17 to which the control pin 87 of thesheath holder 110 shown in FIGS. 5A and 5B is engaged.

When the balloon 516 is expanded, the outer sheath 512 is removed fromthe excising member 500, and then an inflation adapter 532 is, as shownin FIG. 74, connected to the rear end member 522 of the excising member500. In this case, the inflation adapter 532 is screwed in the threadportion 520 of the rear end member 522. An O-ring 530 for keeping airtightness is interposed between the inflation adapter 532 and the rearend member 522. Then, a fluid supply means, such as a syringe (notshown) is connected to a Luer mouth piece 532a at the base portion ofthe inflation adapter 532. In this state, for example, air is suppliedto the inner space of the excising member 500 from the fluid supplymeans. Supplied air is introduced into the balloon 516 through thecommunication hole 510 of the pipe member 514 to expand the balloon 516.Therefore, the excising member 500 having the foregoing structure isable to expand the excision cavity and form a working space permittingtreatment to be performed as well as excising the subcutaneous tissuewithout excessive force for the tissue by expanding the balloon 516.

FIG. 75 shows another structure for expanding the cavity by the balloon516. As illustrated, the folded balloon 516 is accommodated in a ballooncover 545. The outer diameter of the balloon cover 545 is made to besmaller than the maximum outer diameter of the excising member 10 shownin FIGS. 4A and 4B. An engaging groove 540 capable of engaging to theL-shape slit 13a of the excising member 10 is formed in the leading endof the balloon cover 545.

To expand the balloon 516, the engaging groove 540 of the balloon cover545 is hooked by the L-shape slit 13a at the rear end of the excisingmember 10 inserted and retained below the skin. In this state, theballoon cover 545 is inserted into the position below the skin whileperforming traction of the excising member 10. After the balloon cover545 has been completely inserted below the skin, only the balloon cover545 is removed from the position below the skin while holding the rearend of the balloon 516 exposing to the outside through the skin cutportion. In this state, air is supplied to the balloon 516 through theair tube 546 so that the balloon 516 retained in the position below theskin is expanded. Thus, the subcutaneous tissue is dissected and theexcision cavity can be expanded.

The first embodiment is considerably low invasive as compared with therelated art described at the beginning of the specification. However,the skin is inevitably cut for about 4 cm and an excision cavity havinga similar size must be formed below the skin. Thus, according to asecond embodiment, to be described below, there is provided a system forevulsing subcutaneous tissue which is lower invasive as compared withthe first embodiment.

When the blood vessel is evulsed in the second embodiment, for example,when the blood vessel in the lower extremity is evulsed, the skin cutportion E1 is, by a knife or the like, formed in the inguinal region Aof the thigh at a position just above the blood vessel C, such as thesaphenous vein, intended to be extracted and extending from the inguinalregion A of the thigh to the knee D, similarly to the first embodimentand as shown in FIG. 1. In the skin cut portion E1, the blood vessel Cis exposed by forceps or the like. Then, the tissue just above the bloodvessel C is dissected by a similar forceps or the like for a distancewhich can be observed by the naked eye through the skin cut portion E1.

Then, the hard endoscope 20 is inserted and secured to the excisingmember 10 (refer to FIGS. 4A and 4B) according to the first embodiment.In the forgoing insertion and secured state, the leading end 12 of theexcising member 10 is inserted through the skin cut portion E1 in theinguinal region A toward the knee D to move along the upper portion ofthe blood vessel C (see FIGS. 6A and 6B). Since the leading end 12 ofthe excising member 10 is made of a transparent material, the bloodvessel C and the branch F can be observation clearly by the hardendoscope 20. The insertion of the excising member 10 is graduallyperformed in such a manner that the excising member 10 is moved forwardsand rearwards for a short distance while observing the movement of theblood vessel C through the hard endoscope 20. When the excising member10 has been inserted along the blood vessel C to a position near theknee D, the skin just above the leading end 12 of the excising member 10is slightly cut. Then, the leading end 12 of the excising member 10 isejected through the skin cut portion E2.

Then, while leaving the excising member 10 in the body, the hardendoscope 20 is drawn from the excising member 10, and then a tissueprotective tool 30 is attached to the side portion of the excisingmember 10 adjacent to the operator, which is positioned near the skincut portion E1 in the inguinal region A. Then, the excising member 10 ispulled out through the skin cut portion skin cut portion E2, and thetissue protective tool 30 is introduced into the cavity G dissected bythe excising member 10. Note that the tissue protective tool 30 can beinserted without a heavy load because the widthwise cross sectional areaof the tissue protective tool 30 is substantially the same as thewidthwise cross sectional area of the excising member 10. The tissueprotective tool 30 is separated from the excising member 10 after theend portion of the excising member 10 adjacent to the operator's handhas been pulled out through the skin cut portion E2, the tissueprotective tool 30 being then retained in the cavity G (see FIG. 9).

Then, as shown in FIG. 76, the excising member 10 to which the hardendoscope 20 is again attached, is inserted through the skin cut portionE1 along the groove 30a in the upper surface of the tissue protectivetool 30 to be allowed to penetrate to reach the skin cut portion E2,followed by being pulled out. Thus, the cavity G is slightly expanded.Then, a second dissector 10A shown in FIG. 77 is inserted through theskin cut portion E1 to the skin cut portion E2 along the groove 30a inthe upper surface of the tissue protective tool 30, followed by pullingout the second dissector 10A. The leading portion 12A of the seconddissector 10A has the widthwise cross sectional area larger than that ofthe leading end 12 of the excising member 10, as shown in FIG. 78. Thatis to say, the circumferential length of the leading end portion 12A islonger than the circumferential length of the leading portion 12. Theleading portion 12A is made of a transparent material and having a shapelike the leading end 12 of the excising member 10. Therefore, when thesecond dissector 10A has been inserted through the skin cut portion E1and allowed to penetrate to reach the skin cut portion E2, followed bypulling out the second dissector 10A, the dissected cavity G is furtherexpanded to a size into which the cavity maintaining tool 60A can beinserted. That is to say, the second dissector 10A serves as the cavityforming tool.

FIG. 79 shows a cavity maintaining tool 672 according to thisembodiment. As illustrated, the cavity maintaining tool 672 is composedof an outer tube 672A, and two inner tubes 672B and 672C which can beinserted into the outer tube 672A. The outer tube 672A is formed into acylindrical shape having two opened ends. The outer tube 672A has a cuthaving a predetermined depth for, substantially, the overall lengthexcept the two ends thereof. Thus, a side port 673 opened side isformed. It is preferable that the outer diameter of the outer tube 672Ais about 10 mm to about 20 mm. The hard endoscope 20 can be insertedinto the first inner tube 672B of the cavity maintaining tool 672. Thehard endoscope 20 is secured to the inner tube 672B by a fixing screw674 disposed in the portion of the inner tube 672B adjacent to theoperator in a state where the hard endoscope 20 has been inserted intothe inner tube 672B. A treatment tool for treating the blood vessel Cand to be described later can be inserted the inner tube 672C of thecavity maintaining tool 672. To protect the tissue from being damaged,the portions of the two openings of the outer tube 672A and inner tubes672B and 672C have no edges.

FIG. 80 shows an insertion helper 675 detachably attached to the outertube 672A to guide and facilitate insertion of the outer tube 672A. Asillustrated, the insertion helper 675 is composed of a leading portion675a having a tapered leading end; and a support portion 675b detachablyattached to the leading portion 675a by means of threads. The supportportion 675b is composed of an elongated 676 and a near-side portion 677formed in the end portion of the shaft portion 676. A state where theinsertion helper 675 is attached to the outer tube 672A is shown in FIG.81. The procedure will now be described. For example, the shaft portion676 of the insertion helper 675 is inserted into the outer tube 672A,and then the leading portion 675a is screwed in the thread portion ofthe shaft portion 676 projecting through an opening of the outer tube672A in a state where the near-side portion 677 is brought into contactwith the end surface of each opening of the outer tube 672A. Then, theend surface of the leading portion 675a adjacent to the operator isbrought into the end surface of the other opening of the outer tube672A. As a result, the contact state of the leading portion 675a ismaintained by the support portion 675b so that the insertion helper 675is attached to the outer tube 672A while holding the outer tube 672A.The outer tube outer tube 672A, to which the insertion helper 675 hasbeen attached, is inserted and retained in the cavity G expanded by thesecond dissector 10A. When the outer tube 672A is inserted into theinternal cavity G under the skin, the leading portion 675a of theinsertion helper 675 attached to the outer tube 672A is, along thegroove 30a of the tissue protective tool 30, inserted and allowed topenetrate from the skin cut portion E1 to the skin cut portion E2. Then,the insertion helper 675 is removed from the outer tube 672A after thepenetration. The foregoing state is shown in FIG. 82.

After the foregoing operation has been completed, the first and secondinner tubes 672B and 672C are inserted into the outer tube 672A. Then,the tissue protective tool 30 is pulled out from the cavity G. Theforegoing state is shown in FIG. 83. The cross sections of the foregoingstate are shown in FIGS. 84A to 84C. As shown in FIGS. 84A to 84C, inthe state where the cavity maintaining tool 672 is retained under theskin along the blood vessel C, the tissue is raised (forcibly moved) bythe outer tube 672A, and the blood vessel C and the connective tissue300 on the blood vessel C are pushed downwards (forcibly moved) by thefirst and second inner tubes 672B and 672C. Thus, a treatment space(cavity) G for separating the blood vessel C from the connective tissue300 on the blood vessel C is maintained.

In the states shown in FIGS. 84A to 84C, the hard endoscope 20 isinserted into the inner tube 672B, as shown in FIG. 85A. To obtainexcellent visual field for the hard endoscope 20, it is preferable thatthe leading end of the hard endoscope 20 is positioned near the leadingend of the first inner tube 672B in a state where the objective lens ofthe hard endoscope 20 is not in contact with the tissue. That is, it ispreferable that the length of the first inner tube 672B is set to permitthe hard endoscope 20 to be inserted and secured to the first inner tube672B in the foregoing state. An image picked up by the hard endoscope 20in the foregoing preferred state is shown in FIG. 85B. As illustrated,the blood vessel C and the branch F can be clearly observed. Moreover,the second inner tube 672C can be observed at a distant position.

By moving the first inner tube 672B in the outer tube 672A in the stateshown in FIG. 85A, a cavity G under the skin from the skin cut portionE1 to the skin cut portion E2 can be observed. By changing the distancefrom the first inner tube 672B to the second inner tube inner tube 672C,the size of the treatment (cavity) G can be adjusted. FIG. 86A shows astate where the opening/closing type hook probe 130 shown in FIG. 20 hasbeen inserted into the treatment (cavity) G through the second innertube 672C to dissect the blood vessel C from the connective tissue 300on the blood vessel C. An image picked up by the hard endoscope 20 atthis time is shown in FIG. 86B. As can be understood from FIG. 86B,movement of the opening/closing type hook probe 130 to the right resultsin the opening/ closing type hook probe 130 being moved to the left inthe image picked up by the endoscope 20 because the opening/closing typehook probe 130 and the hard endoscope 20 are inserted from the oppositepositions of the outer tube 672A. Therefore, the opening/closing typehook probe 130 cannot easily be operated.

Accordingly, this embodiment uses an endoscope system 700 shown in FIG.87. In the endoscope system 700, an image picked up by the hardendoscope 20 is, through a video adapter 701 having an optical systembent perpendicularly, transmitted to a TV camera 702 including an imagepickup device (not shown) so that the optical signal is converted intoan electric signal and then transmitted to a CCU (Camera Control Unit)703. A signal from the CCU 703 is transmitted to an image inverting unit704 so as to be converted into an image, the right-hand portion and theleft-hand portion are inverted, followed by being transmitted to themonitor 705. Therefore, the operator is able to observe an image whichcoincides with the direction of the actual movement of the treatmenttool.

In the case where the blood vessel C is dissected from the connectivetissue 300 by the opening/closing type hook probe 130, the front hooks135 and 136 of the opening/closing type hook probe 130 are closed whileobserving the image which coincides with the actual movement of thetreatment tool. In the foregoing state, the leading hooks 135 and 136are inserted into the surrounding tissue 300, followed by moving underthe blood vessel C to penetrate to reach the opposite portion (see FIG.86B). In the foregoing state, the hooks 135 and 136 are gradually openedso as to dissect the blood vessel C from the surrounding tissue 300. Thestate where the blood vessel C has been dissected from the surroundingtissue 300 is shown in FIG. 88A. The foregoing operation is performedfor the length of the blood vessel C intended to be evulsed. In thiscase, an excising forceps for a body cavity mirror (not shown) may beused, if necessary.

After the blood vessel C has been dissected for the length to be evulsed(for example, about 25 cm), clips 96 are attached to two portions of thebranch F (see FIG. 88B), and then the branch F between the clips 96 iscut by the forceps (see FIG. 88C). The operation of cutting the branch Fis performed for the length of the blood vessel C intended to be evulsedso that the blood vessel C is evulsed to the outside of the body. If alonger blood vessel is required to be evulsed, a similar operation isrequired to be performed repeatedly. In this case, the blood vessel Cfrom the inguinal region A to the ankle can be evulsed.

As described above, according to this embodiment, the blood vessel caneasily be evulsed from a very small skin cut portion without damage ofthe blood vessel. This embodiment enables nerve below the skin to beevulsed, as well as the blood vessel.

FIGS. 89, 90A and 90B show a first modification of the secondembodiment. The first modification is deformation of the cavitymaintaining tool 672 according to the second embodiment. The residualstructures and operation are the same as those of the second embodiment.As shown in FIG. 89, the cavity maintaining tool 680 according to thismodification is formed into a cylindrical shape. The side surface of thecentral portion of the cavity maintaining tool 680 is cut to have apredetermined depth. Thus, a side port 681 opened in the side portion toform the treatment space (cavity) G is formed. The method of insertingand retaining the cavity maintaining tool 680 in the cavity under theskin and the endoscope system for obtaining an inverted image are thesame as those according to the second embodiment.

FIG. 90A shows a state where the cavity maintaining tool 680 is retainedin the cavity under the skin. FIG. 90B shows an image picked up by thehard endoscope 20 inserted into the cavity maintaining tool 680. Bymoving the side port 681 of the cavity maintaining tool 680 from skincut portion E1 to skin cut portion E2, the overall body of the bloodvessel C can be observed and treated. Note that the method of separatingthe blood vessel C from the surrounding tissue 300 is the same as thataccording to the second embodiment.

FIGS. 91A and 91B show a second modification of the second embodiment.This modification is a modification of the cavity maintaining tool 680according to the first modification. The other structures and operationsare the same as those of the first modification. As illustrated, acavity maintaining tool 690 according to this modification is compose ofa cylindrical body 690a and extension portions 690 b respectivelydetachable to the two ends of the body 690a by screws. The side surfaceof the central of the body 690a is cut to have a predetermined depth sothat a side port 691 opened to the side portion so as to form thetreatment space (cavity) G is formed. Therefore, the cavity maintainingtool 690 according to this modification has a similar shape as thecavity maintaining tool 680 according to the first modification in astate where the body 690a and the extension portions 690 b.

The cavity maintaining tool 680 according to the first modification hasa relatively long overall length, while the cavity maintaining tool 690according to the second modification is enabled to have the overalllength which can be adjusted to correspond to the length of thetreatment region due to employment of a separation type structure. Thus,the operation can smoothly be performed. If a plurality of extensionportions 690 b having various lengths are prepared, they can selectivelybe employed having an optimum length to be adaptable to the length ofthe employed treatment tool. Thus, the operation can further smoothly beperformed.

FIGS. 92 to 99B show a third modification of the second embodiment. Thismodification is a modification of the cavity maintaining tool 672according to the second embodiment. Therefore, the same element as thoseaccording to the second embodiment are given the same reference numeralsand they are omitted from illustration. As shown in FIG. 92, an outertube 672A of a cavity maintaining tool 672' according to thismodification has cut portions 810 in the cylindrical portions 801 at thetwo ends across the side port 673. The cut portions 810 are formed forthe overall length of the cylindrical portions 801. As shown in FIG. 93,a projection 804 having a recess 803 in the central portion thereof isformed in the leading end of each of the first and second inner tubes672B and 672C. FIG. 94 shows a state where the insertion helper 675shown in FIG. 80 is attached to the outer tube 672A of the cavitymaintaining tool 672'. FIG. 95 shows a state where the leading portion675a of the insertion helper 675 has been inserted along the groove 30aof the tissue protective tool 30 to penetrate from skin cut portion E1to skin cut portion E2, and then the insertion helper 675 has beenremoved from the outer tube 672A. FIG. 96 shows a state where the firstinner tube 672B and the second inner tube 672C of the cavity maintainingtool 672' according to this modification have been inserted into theouter tube 672A in the state shown in FIG. 95 and the tissue protectivetool 30 has been pulled out from the cavity G. Cross sectional views inthe foregoing state are shown in FIGS. 97A to 97C. In this embodiment,insertion of the first and second inner tubes 672B and 672C of thecavity maintaining tool 672' according to this modification into theouter tube 672A is performed in a state where the projections 804 of thefirst and second inner tubes 672B and 672C have been inserted into cutportions 810 of the outer tube 672A. In the foregoing case, the recess803 of the projection 804 is moved along the blood vessel C. As shown inFIGS. 97A to 97C, in a state where the cavity maintaining tool 672' isretained under the skin along the blood vessel C, the tissue is slightlyraised (forcibly moved) by the outer tube 672A and the blood vessel Cand the surrounding tissue 300 are pushed downwards (forcibly moved) bythe first and second inner tubes 672B and 672C. As a result, a treatmentspace (cavity) G permitting treatment for separating the blood vessel Cfrom the surrounding tissue 300 is maintained. In particular, theprojections 804 of the first and second inner tubes 672B and 672C holdthe two ends (tissue on the two sides) of the blood vessel C at thecentral recesses 803.

A state where the hard endoscope 20 has been inserted into the firstinner tube 672B in the state shown in FIGS. 97A to 97C is shown in FIG.98A. An image picked by the hard endoscope 20 at this time is shown inFIG. 98B. FIG. 99A shows a state where the opening/closing type hookprobe 130 shown in FIG. 20 has been inserted into a treatment space(cavity) G through the second inner tube 672C to dissect the bloodvessel C from the surrounding tissue 300. An image picked up by theendoscope 20 at this time is shown in FIG. 99B. As can be understoodfrom FIG. 99B, since the recess 803 of the projection 804 of the firstand second first inner tubes 672B and 672C hold two ends (tissue on thetwo sides) of the blood vessel C, the blood vessel C is allowed toproject over the surrounding tissue. Thus, the leading hooks 135 and 136can easily be introduced into the surrounding tissue 300 to move underthe blood vessel C.

FIGS. 100, 101A and 101B show a fourth modification of the secondembodiment. A cavity maintaining tool 680' according to thismodification has recess portions 820 in the lower portion adjacent tothe side port 681 of the cavity maintaining tool 680 according to thefirst modification to be place along the blood vessel C and to raise theblood vessel C from the surrounding tissue. The residual structures andoperations are the same as those of the first modification.

FIGS. 102A and 102B show a fifth modification of the second embodiment.A cavity maintaining tool 690' according to this modification has recessportions 820 in the lower portion adjacent to the side port 681 of thecavity maintaining tool 680 according to the first modification to beplace along the blood vessel C and to raise the blood vessel C from thesurrounding tissue. The residual structures and operations are the sameas those of the first modification.

FIGS. 103A, 103B, 104A and 104B show a modification of the excisingmember 10 and the sheath holder 110 according to the first embodiment.As shown in FIGS. 103A and 103B, the rotation-stopping groove 17 to beengaged to the control pin 87 of the sheath holder 110B shown in FIGS.104A and 104B is disposed in the lower portion of the base portion ofthe large-diameter pipe 13 of the excising member 10B. Therefore, whenthe excising member 10B has been attached to the hard endoscope 20, theposition of the excising member 10 in the direction of rotation canautomatically be determined. Moreover, the large-diameter pipe 13 hasthe slit 13a for hooking the tissue protective tool 30 shown in FIG. 7A.A state where the sheath holder 110B and the excising member 10B havebeen attached to the hard endoscope 20 is shown in FIGS. 104A and 104B.The attaching method in this case is the same as that according to thefirst embodiment.

FIGS. 105A to 105C show a modification of the cavity maintaining tool 60according to the first embodiment. As illustrated, the rear end 61a ofthe cavity maintaining tool 60 has the openings 62a and the arch-shapebases 62c having an opening 62b for an endoscope, into which the hardendoscope 20 is inserted. The leading end 61b has a leading end 62d inthe form obtained by dividing a conical cylinder in the radialdirection. A guide projection 60a is formed in the lower surface of theleading portion 62d so as to be received by the groove 30a of the tissueprotective tool 30. Four hard shafts 62e and the endoscope guide tube62f which can be inserted into the hard endoscope 20 are disposedbetween the bases 62c and the leading portion 62d. Therefore, a sideopening 62g is formed for the overall length of the cavity maintainingtool 60 by the shafts 62e, the base 62c and the leading portion 62d.

FIGS. 106 to 113 show an endoscope hood serving as an excising memberadaptable to the system for evulsing subcutaneous tissue according tothe present invention. FIGS. 106 to 107E show a first embodiment of theendoscope hood. FIG. 106 shows a schematic structure of a sheath 901having a transparent hood, which is the endoscope hood according to thisembodiment and a hard endoscope 902 to be inserted into the sheath 901.The sheath 901 having a transparent hood has a double cylinderconsisting of an inner cylinder 903 and an outer cylinder 904 disposedaround the inner cylinder 903. The inner cylinder 903 is made to belonger the outer cylinder 904. The two ends of the inner cylinder 903extend to the outsides of the two ends of the outer cylinder 904. Theinner cylinder 903 has, at the leading end thereof, a transparent hood(body) 905, while the inner cylinder 903 has, at the rear end thereof,an endoscope fixing portion 906. The inner diameter of the innercylinder 903 is determined to permit the endoscope 902 to be inserted.The transparent hood 905 has a fixed hood 907 to be secured to theleading end of the inner cylinder 903 and having a cylindrical shape anda movable hood 908. The fixed hood 907 and the movable hood 908 are madeof transparent material (light transmissive material), such as a resin,such as acrylic resin, polycarbonate or polysulfone; or glass. In astate where the hard endoscope 902 has been inserted into the innercylinder 903, an image can be observed with the hard endoscope 902through the wall of the transparent hood 905.

The cylindrical fixed hood 907 has a cut portion 909 in the lowerportion of the leading end thereof. The movable hood 908 has an engagingportion 910 having a shape corresponding to the cut portion 909 of thecylindrical fixed hood 907. The base portion of the movable hood 908 isrotatively connected to the fixed hood 907 by a hinge 911 comprising arotational pin. A rod connection portion 912 projects over the outersurface of the movable hood 908. The leading end of the operation rod913 for opening/closing the movable hood 908 is attached to the rodconnection portion 912 by a fixing pin 914. Moreover, the base portionof the operation rod 913 is secured to the outer surface of the leadingend of the outer cylinder 904.

A wedge-like pushing portion 915 is, as shown in FIG. 107A, formed atthe leading end of the movable hood 908. A first electrode 917 isattached to an edge portion 916 at the leading end of the pushingportion 915. In the vicinity of the first electrode 917, a secondelectrode 918 is attached. The width of the first electrode 917 issmaller than the diameter of the transparent hood 905. The surface areaof the first electrode 917 is smaller than that of the second electrode918. A bipolar incising and coagulation means for incising andcoagulating an organic tissue by allowing high-frequency cauterizationcurrent between the first electrode 917 and the second electrode 918 isformed.

A cord 919 connected to the two electrodes 917 and 918 is allowed topass between the inner cylinder 903 and the outer cylinder 904, followedby being deduced to the outside through a cord insertion hole 920 formedin the outer surface at the rear end of the outer cylinder 904. Then,the cord 919 is connected to a power supply unit (not shown) forsupplying the cauterization current. A flange portion 921 is, as shownin FIG. 107C, formed in the inner end portion of an engaging portion 910of the movable hood 908 to be engaged to a cut portion 909 of the fixedhood 908. For example, a rubber member, such as silicon rubber or asealing means 922 applied with grease or the like is provided for theflange portion 921. When the movable hood 908 is engaged in a state thecut portion 909 of the fixed hood 908 is closed, air tightness betweenthe fixed hood 908 and the movable hood 908 can be maintained by thesealing means 922.

An inner cylinder connection portion 923 to cover the rear end of theinner cylinder 903 is provided for the endoscope fixing portion 906. Atube-like sealing member 924 is provided on the inner surface of therear end of the inner cylinder connection portion 923. Moreover, aprojection 925 is allowed to project over the outer surface of the rearend of the inner cylinder connection portion 923 in a directionperpendicular to the axial direction of the inner cylinder 903. A screwmember 926 of the sealing member 924 is attached to the projection 925.After the hard endoscope 902 has been inserted into the inner cylinder903, the screw member 926 is tightened so that the sealing member 924 isclamped and secured to the outer surface of the hard endoscope 902.Thus, the hard endoscope 902 is hermetically secured. An air supply port927 communicated with the inner space of the inner cylinder 903 isallowed to project over the outer surface of the leading end of theinner cylinder connection portion 923. Moreover, an inner cylinderfixing portion 928 is formed at the rear end of the outer cylinder 904.The inner cylinder fixing portion 928 has an outer cylinder connectionportion 929 for covering the rear end of the outer cylinder 904. Atubular sealing member 930 made of rubber or the like is provided on theinner surface of the rear end of the outer cylinder connection portion929. A projection 931 is allowed to project over the outer surface ofthe rear end of the inner cylinder fixing portion 928 in a directionperpendicular to the axial direction of the outer cylinder 904. A screwmember 932 for clamping the sealing member 930 is attached to theprojection 931. After the inner cylinder 903 has been inserted into theouter cylinder 904, the screw member 932 is clamped so that the sealingmember 930 is clamped and secured to the outer surface of the innercylinder 903 so that the inner cylinder 903 is hermetically secured. Byrotating the screw member 932 in a direction opposite to the clampingdirection to loosen clamping of the sealing member 930 to the outersurface of the inner cylinder 903, the sealing member 930 of the outercylinder 904 can be slid along the inner cylinder 903. As a result, theposition at which the outer cylinder 904 is fixed to the inner cylinder903 can arbitrarily adjusted in the axial direction of the innercylinder 903. A conical airtight member 933 is formed on the outersurface of the outer cylinder 904. An annular sealing member 934 capableof hermetically sliding on the outer surface of the outer cylinder 904is disposed at the rear end of the airtight member 933. The sealingmember 934 is secured to the rear end of the airtight member 933 in astate where it is held between a fixing member 935, to be screw-fixed tothe rear end of the airtight member 933, and the airtight member 933.Moreover, a pair of suture receiving portions 936 are formed on theouter surface of the rear end of the airtight member 933.

The operation of the foregoing structure will now be described. Aprocedure will now be described in which the hard endoscope 902 is, fromthe skin of a patient, inserted into organic tissue X in the bodythrough the muscular tunics to observe and treat the spine, as shown inFIGS. 107B and 107C. Initially, the hard endoscope 902 is inserted intothe sheath 901 having a transparent hood, and then the screw member 926is clamped and secured. Then, a small cut portion, that is, a skin cutportion, having a size which permits the sheath 901 having a transparenthood to be inserted, is formed in the skin of the patient so as toexpose the muscular tunics in the body. In this state, the sheath 901having a transparent hood is pushed in while aligning the edge portion916 of the transparent hood 905 through the cut portion in the skin ofthe patient, the muscular tissue is dissected. Thus, as shown in FIG.107B, the leading end of the sheath 901 having a transparent hood isinserted into the organic tissue X in the body. Since the state of theorganic tissue X can be observed at this time through the transparentwall of the transparent hood 905 with the hard endoscope 902 in thesheath 901, the excision operation can be performed safely whileconfirming the position of the blood vessel and the like. FIG. 107Dshows an image of the organic tissue X observed through the transparentwall of the transparent hood 905 with the hard endoscope 902 during theoperation of inserting the sheath 901 having a transparent hood.

If the leading end of the transparent hood 905 comes in contact with thefasciae or hard tissue during the operation of inserting the leading endof the sheath 901 having a transparent hood, the high-frequencycauterization current is allowed to flow through the first electrode 917and the second electrode 918. The current is allowed to flow by thebipolar method to the first and second electrodes 917 and 918. Since thecurrent is allowed to flow through the two electrodes 917 and 918, theoperation can be performed safely. Since the surface area of the firstelectrode 917 is smaller than that of the second electrode 918, densityof the current per unit area is raised. Therefore, the organic tissue Xcan be cauterized concentrically in the portion adjacent to the firstelectrode 917. Thus, the organic tissue X can be incised and coagulatedso that even the fasciae and hard organic tissue are dissected. Sincethe first electrode 917 is disposed adjacent to the leading end of themovable hood 908 and the edge portion 916, the cauterized portion of theorganic tissue X can easily be dissected by the edge portion 916.Therefore, the excising operation can further easily be performed. Sincethe width of the first electrode 917 is made to be smaller than thediameter of the transparent hood 905, an experiment resulted in that thewedge-like pushing portion 915 of the sheath 901 having a transparenthood having a diameter of ten-odd mm can be inserted into the body if acut portion having a size of about 3 mm is formed in the skin of thepatient in the case of the muscular tunics. Therefore, the sheath 901having a transparent hood can be inserted into the body whilenecessitating a smaller incision and coagulation of the organic tissue Xof the patient. Moreover, during the operation of inserting the sheath901 having a transparent hood into the body, the state of the incisionand coagulation of the organic tissue X can be confirmed with the hardendoscope 902 through the transparent wall of the transparent hood 905.Thereof, the operation can safely be performed.

Even if bleeding takes place, it can be stopped by abutting the firstelectrode 917 and the second electrode 918 at the leading end of thetransparent hood 905 against the bleeding portion. Therefore, anothertool for stopping bleeding is not required. Thus, the operation ofexcising the organic tissue X can smoothly be performed. In the statewhere the engaging portion 910 of the movable hood 908 has been engagedto the cut portion 909 of the fixed hood 907, the sealing means 922provided for the flange portion 921 at the inner end of the engagingportion 910 of the movable hood 908 prevents introduction of blood intothe transparent hood 905 through the joint portion between the fixedhood 907 and the movable hood 908. Therefore, contamination of the hardendoscope 902 in the sheath 901 having a transparent hood can beprevented. When the sheath 901 having a transparent hood has reached thespine Y, the airtight member 933 is slide along the outer surface of theouter cylinder 904 toward the leading end to bring the same into contactwith the portion around the small cut portion in the skin. In theforegoing state, a suture is used to suture the skin from the suturereceiving portion 936 and the skin, and then the airtight member 933 issecured to the skin.

Then, the outer cylinder 904 is moved with respect to the inner cylinder903. At this time, the operation rod 913 is pulled rearwards due to themovement of the outer cylinder 904. Therefore, the movable hood 908 isrotated relative to the hinge 911 so that the movable hood 908 is openeddownwards with respect to the fixed hood 907. In this state, CO₂ gas orthe like is supplied into the body from the air supply port 927 of thesheath 901 having a transparent hood at a position near the operatorthrough the inner cylinder 903. As a result, the portion, which has beendissected due to the opening of the movable hood 908, is further openeddue to the supply of the gas. Thus, space S in the body required toperform the observation and treatment of the spine Y is maintained, asshown in FIG. 107C. Since the movable hood 908 has been opened downwardswith respect to the fixed hood 907 at this time, the spine Y candirectly be observed with the hard endoscope 902 in the sheath 901without transmission through the transparent wall of the transparenthood 905. Therefore, a clear visual field can be obtained with the hardendoscope 902. FIG. 107E shows an image of the spine Y which has beendirectly observed with the hard endoscope 902 in the sheath 901 having atransparent hood without transmission through the transparent wall ofthe transparent hood 905.

In a case where the organic tissue X in the body is observed with thehard endoscope 902 in the sheath 901 having a transparent hood throughthe transparent wall of the transparent hood 905, organic tissue X inclosely contact with the transparent hood 905 can be observed clearly.However, the visual field of the organic tissue X apart from thetransparent hood 905 is unsatisfactory to easily observe the organictissue X. Therefore, the structure of this embodiment in which themovable hood 908 is opened downwards with respect to the fixed hood 907enables the organic tissue X, intended to be observed, to be directlyobserved with the hard endoscope 902. Thus, the organic tissue X can beobserved and treated satisfactorily. In a case where the fogging of thesurface of the glass of the observation optical system of the endoscope902 and the visual field of the hard endoscope 902 has becomeunsatisfactory, CO₂ gas or the like is supplied in a state where themovable hood 908 of the transparent hood 905 is slightly opened. Thus,fogging of the surface of the glass of the observation optical systemcan effectively be overcome. A fact has been known that dry gas issprayed against the surface of the glass of the observation opticalsystem at the leading end of the hard endoscope 902 to prevent fogging.However, this embodiment has the structure such that the portion aroundthe leading end of the hard endoscope 902 is surrounded by thetransparent hood 905 enables the surface of the glass of the observationoptical system at the leading end of the endoscope 902 to be efficientlyexposed to dry gas only by supplying a little quantity of dry gas into asmall space formed in the transparent hood 905. Therefore, fogging canfurther effectively be overcome and prevented.

Thus, the foregoing structure attains the following advantages. That is,since the bipolar type first electrode 917 and the second electrode 918forming the incising and coagulating means are provided for the edgeportion 916 of the movable hood 908 of the transparent hood 905, theorganic tissue X can be incised and coagulated by allowing thehigh-frequency cauterization current to flow between the first electrode917 and the second electrode 918 during the operation of inserting thehard endoscope 902 into the body. Therefore, the organic tissue X canefficiently be dissected. Since the surface area of the first electrode917 is made to be smaller than the second electrode 918 to raise thedensity of the current per unit area, the organic tissue X can becauterized concentrically in the portion near the first electrode 917.Therefore, the organic tissue X can efficiently be dissected whilenecessitating only a small incision and coagulation ranges.

Since the organic tissue X can directly be observed with the eye withthe hard endoscope 902 in the sheath 901 having a transparent hoodthrough the transparent wall of the transparent hood 905 when theoperation of excising the organic tissue X is performed, the operationof excising the organic tissue X and the operation of stopping bleedingcan safely and easily be performed. Since the movable hood 908 is openeddownwards with respect to the fixed hood 907 after the organic tissue Xhas been dissected, the organic tissue X intended to be observed can beobserved directly with the hard endoscope 902. Therefore, the organictissue X can directly be observed with the hard endoscope 902 in thesheath 901 having a transparent hood without transmission through thetransparent wall of the transparent hood 905. Therefore, a clear visualfield can be obtained through the hard endoscope 902. Since CO₂ gas orthe like is supplied into the body through the inner cylinder 903 in astate where the movable hood 908 has been opened with respect to thefixed hood 907, the dissected portion can further be expanded due to thesupply of the gas. Therefore, the space S in the body required toobserve and treat the spine Y can satisfactorily be maintained. Sincethe CO₂ gas is supplied into the body through the inner cylinder 903,fogging of the surface of the glass of the observation optical system ofthe hard endoscope 902 can be overcome and prevented.

Although this embodiment has the structure such that the bipolar typefirst electrode 917 and the second electrode 918 forming the incisingand coagulating means are provided for the edge portion 916 of themovable hood 908 of the transparent hood 905, the incising andcoagulating means may be formed by a monopolar type structure includingone unified electrode while having a similar structure. Although thisembodiment has the structure such that the bipolar type first electrode917 and the second electrode 918 are directly secured to the surface ofthe movable hood 908 of the transparent hood 905, a heat insulatingmaterial member made of fluorine resin or ceramic may be disposedbetween the movable hood 908 and the electrodes 917 and 918. If thetransparent heating insulating material member made of the fluorineresin is employed, the visual field of the hard endoscope 902 cannot bedeteriorated. In place of the electrodes 917 and 918, an antenna forgenerating microwaves may be employed to obtain a similar effect.

FIG. 108A shows a second embodiment of the endoscope hood. A transparentsheath 951, which is an endoscope hood, has a sheath body 952 in theform of a cylindrical shape having a closed leading end formed into aconical shape and made of a transparent material. A heat generatingmeans (incising and coagulating means) 953 is attached to the leadingend of the sheath body 952. As the heat generating means 953, astructure is employed in which a heater for generating heat when anelectric current is allowed to flow is coated with, for example, afluorine resin to prevent burning. The heat generating means 953 is,through a lead wire 954 disposed on the outer surface of the sheath body952, connected to a connector 955 for establishing the connection withthe power source. The lead wire 954 may be embedded in the outer surfaceof the sheath body 952 or disposed in the sheath body 952. Therefore,the foregoing structure enables the organic tissue to be dissected bypushing in the sheath body 952 in a state where the leading end of thesheath body 952 of the transparent sheath 951 is in contact with theorganic tissue. By allowing electric current to flow to the heatgenerating means 953 at the leading end of the sheath body 952, theorganic tissue can be cauterized or stopping of bleeding can be stopped.Although the second embodiment has the structure such that the heatgenerating means 953 is directly secured to the surface of the sheathbody 952 of the transparent sheath 951, a heat insulating materialmember, made of a fluorine resin or ceramic may be inserted between thesheath body 952 and the heat generating means 953. If the transparentheat insulating material, such as the fluorine resin, is employed, anexcellent visual field of the endoscope 902 can be obtained.

FIG. 108B shows a third embodiment of the endoscope hood. A transparentsheath, which is the endoscope hood, according to this embodiment is asupersonic sheath 961 capable of incising and coagulating an organictissue. The supersonic sheath (incising and coagulating means) 961 isprovided with an elongated pipe-like probe 963 into which an endoscope962 can be inserted. A supersonic oscillator 964 is connected to thebase portion of the probe 963. The supersonic oscillator 964 has anendoscope insertion hole 965 into which the endoscope 962 can beinserted. A transparent hood (hood body) 966 is attached to the leadingend of the probe 963. Therefore, in the foregoing structure, supersonicoscillations generated by the supersonic oscillator 964 are transmittedto the transparent hood 966 through the probe 963. Thus, the organictissue, with which the transparent hood 966 is in contact can be incisedand coagulated.

FIG. 108C shows a fourth embodiment of the endoscope hood. Thisembodiment is a modification of the third embodiment. That is, thisembodiment has the structure such that a cut portion 971 cut diagonallywith respect to the axial line of a probe 963 according to thisembodiment is formed at the leading end of the probe 963. Moreover, atransparent member (hood body) 972, which is an endoscope hood, isdisposed on the inside of the cut portion 971 at the leading end of theprobe 963. Therefore, the foregoing structure enables the organic tissueto be directly incised and coagulated by the probe 963. Therefore, thesupersonic oscillation can efficiently be transmitted to the organictissue. Note that the transmission efficiency of the supersonicoscillation is considerably affected by the material of the probe 963.Therefore, in the case where the probe 963 is direction brought into theorganic tissue as is performed in this embodiment, excision and stoppingof bleeding can effectively be performed as compared with the structureof, for example, the supersonic sheath 961 according to the thirdembodiment in which the supersonic oscillation from the probe 963 istransmitted to the organic tissue through the transparent hood 966.

FIG. 109 shows a fifth embodiment of the endoscope hood. A transparentsheath 981, which is the endoscope hood according to this embodiment,has a sheath body 982 provided with an endoscope insertion hole 983having a closed leading end and an endoscope insertion hole 983 havingtwo opened ends. The endoscope 985 is inserted into the endoscopeinsertion hole 983 and a supersonic probe (incising and coagulatingmeans) 986 is inserted into the treatment tool hole 984. Therefore, theforegoing structure enables the organic tissue to be directly be incisedand coagulated by the supersonic probe 986. Therefore, the supersonicoscillation can efficiently be transmitted to the organic tissue.

FIGS. 110A to 110D show a sixth embodiment of the endoscope hood. Theendoscope hood according to this embodiment is a transparent sheath 993in the form of a double cylinder consisting of an outer sheath 991 madeof a transparent material and a transparent inner sheath 992 insertedinto the outer sheath 991. The outer sheath 991 has, at the leading endthereof, a pushing portion 994 in the shape of a closed wedge. Moreover,a graven-line portion 995 extending in the axial direction of the outersheath 991 is formed on the outer surface of the leading end of theouter sheath 991, as shown in FIG. 110C. The leading end of the innersheath 992 is held in a state where the same has been inserted to aposition near the pushing portion 994 of the outer sheath 991. Anendoscope 996 can be inserted into the inner sheath 992. Therefore, in astate of the foregoing structure in which the leading end of the innersheath 992 is, as shown in FIG. 110B, held while being inserted to aposition near the pushing portion 994 of the outer sheath 991, theendoscope 996 is inserted into the inner sheath 992. Thus, state of theorganic tissue can be observed with the endoscope 996 in the transparentsheath 993 through the transparent wall of the pushing portion 994 ofthe outer sheath 991. Since the graven-line portion 995 at the leadingend of the outer sheath 991 has not been broken, the inside portion ofthe outer sheath 991 can be maintained to a water-tight state.Therefore, water introduction into the outer sheath 991 can beprevented. When the inner sheath 992 is slid forwards with respect tothe outer sheath 991, the graven-line portion 995 of the outer sheath991 is broken so that the inner sheath 992 is allowed to project, asshown in FIG. 110D. Therefore, in the foregoing case, the organic tissuecan directly be observed with the endoscope 996 in the transparentsheath 993 without transmission of the transparent wall of the pushingportion 994 of the outer sheath 991. Thereof, a clear visual field canbe obtained with the endoscope 996. By somewhat pulling inward theleading end of the endoscope 996 toward the inside portion of the innersheath 992 from the leading end of the inner sheath 992, contaminationof the endoscope 996 due to contact with the organic tissue can beprevented even if the outer sheath 991 has been opened. In place of thegraven-line portion 995 formed in the outer sheath 991, slits may beformed in the outer surface of the outer sheath 991; and the slitportion is sealed by a sealing agent such as rubber or an adhesive agentto obtain a similar effect.

FIGS. 111A, 111B and 112 show a seventh embodiment of the endoscopehood. The endoscope hood according to this embodiment is a transparentsheath 1001 suitable to insert a diagonal-view or side-view typeendoscope. The sheath body 1002 of the transparent sheath 1001 has alower opening 1003 in the opening portion in the lower surface thereof.Moreover, a transparent shutter member 1004 is attached to the loweropening 1003 in such a manner that the shutter member 1004 can be openedand closed. A shutter guide groove 1005 is, as shown in FIG. 7, formedin the surface of the lower opening 1003. The shutter member 1004 isreceived in the shutter guide groove 1005. Note that a water sealingmember, such as rubber or grease, maintains water sealing between theshutter guide groove 1005 and the shutter member 1004. A leading end ofan operation rod 1006 is secured to the shutter member 1004. The baseportion of the operation rod 1006 is connected to an operation ring 1007slidably disposed on the outer surface of the sheath body 1002 of thetransparent sheath 1001. By rearwards sliding the operation ring 1007,the shutter member 1004 is, as shown in FIG. 111B, rearwards slid sothat the lower opening 1003 of the sheath body 1002 is opened.

Therefore, in a state of this embodiment, as shown in FIG. 111A, inwhich the lower opening 1003 of the sheath body 1002 of the transparentsheath 1001 is closed by the shutter member 1004, the diagonal-view typeor side-view type endoscope is inserted. Thus, state of the organictissue can be observed through the transparent wall of the shuttermember 1004 with the diagonal-view type or side-view type endoscope.Since the space between the shutter guide groove 1005 and the shuttermember 1004 is sealed against water by the sealing member against water,such as rubber or grease, the inside portion of the sheath body 1002 canbe sealed against water. Thus, introduction of liquid into the sheathbody 1002 can be prevented. By rearwards sliding the operation ring 1007to rearwards slide the shutter member 1004 as shown in FIG. 111B, thelower opening 1003 of the sheath body 1002 is opened. Therefore, in theforegoing case, the organic tissue can directly be observed through thelower opening 1003 of the sheath body 1002 by the diagonal-view type orside-view type endoscope in the transparent sheath 1001 withouttransmission through the transparent wall of the shutter member 1004.Thus, a clear visual field can be obtained with the diagonal-view typeor side-view type endoscope diagonal-view type or side-view typeendoscope. Since the leading end of the diagonal-view type or side-viewtype endoscope is accommodated in the sheath body 1002 at this time, theleading end of the diagonal-view type or side-view type endoscope doesnot project over the sheath body 1002. Therefore, contamination due tocontact of the diagonal-view type or side-view type endoscope with theorganic tissue can be prevented during the period in which the shuttermember 1004 is opened.

FIGS. 113A and 113B show an eighth embodiment of the endoscope hood. Asheath 1010, which is the endoscope hood according to this embodiment,is made of a transparent material and has a wedge-like leading end. Thesheath 1010 has an opening 1011. An endoscope 1012 is a diagonal-viewtype endoscope. As shown in FIG. 113A, observation can be performedthrough an opening 1011. By rotating the endoscope 1012 by 180° toslightly rearwards move, observation through the transparent portion ofthe sheath 1010 can be performed, as shown in FIG. 113B.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, representative devices, andillustrated examples shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A system for evulsing subcutaneous tissue,comprising:an endoscope adapted to be inserted into subcutaneous tissuethrough a skin cut portion to observe tissue to be evulsed and existingunder the skin; a dissecting unit adapted to be inserted into thesubcutaneous tissue through said skin cut portion so as to dissect thetissue, to be evulsed, from surrounding tissue in order to form a cavityalong the tissue to be evulsed and below the skin; a tunnel-shapedcavity maintaining unit adapted to be inserted from said skin cutportion into the cavity formed by said dissecting unit and to beretained in the cavity in order to maintain, by itself and without anyexternal means connected thereto to support said tunnel-shaped cavitymaintaining unit, around the tissue to be evulsed, a treatment spacewhich permits said endoscope to be inserted and removed and whichenables treatment of the tissue to be evulsed to be performed; and atleast one treatment tool adapted to be inserted into the treatment spacemaintained by said cavity maintaining unit in order to perform, in thetreatment space, treatment required to evulse the tissue to be evulsed.2. A system for evulsing subcutaneous tissue according to claim 1,wherein:said dissecting unit comprises: a dissector having an insertionpassage which permits said endoscope to be inserted, which is insertableinto the subcutaneous tissue through the skin cut portion together withthe endoscope and which forms the cavity along the tissue to be evulsedand below the skin while dissecting tissue adjacent to the tissue, to beevulsed, under observation with said endoscope; a tissue protective unitadapted to be inserted into the cavity formed by said dissector from theskin cut portion to be retained in the cavity so as to cover and protectthe tissue to be evulsed; and an expansion unit adapted to be insertedinto the cavity formed by said dissector from the skin cut portion toexpand the cavity formed by said dissector around the tissue to beevulsed and protected by said tissue protective unit.
 3. A system forevulsing subcutaneous tissue according to claim 1, wherein saiddissecting unit comprises:an elongated tubular member having aninsertion hole through which said endoscope can be inserted, and anobservation portion which is formed at least in a portion of saidtubular member and which permits observation with said endoscope, andwherein the shape of a leading end of said tubular member is formed tobe smooth so as to be capable of dissecting the tissue to be evulsed insuch a manner that said tubular member does not damage the tissue to beevulsed.
 4. A system for evulsing subcutaneous tissue according to claim2, wherein said tissue protecting unit comprises a guide unit forguiding said expansion unit and said cavity maintaining unit to beinserted into the cavity formed around the tissue to be evulsed.
 5. Asystem for evulsing subcutaneous tissue according to claim 2, whereinsaid dissector comprises, at a position near an operator, a connectionportion which can detachably be connected to said tissue protectiveunit.
 6. A system for evulsing subcutaneous tissue according to claim 2,wherein:said expansion unit comprises: a substantially flat body portionadapted to be inserted into the cavity formed around the tissue to beevulsed so as to expand the cavity while dissecting tissue around thetissue to be evulsed, and an operation rod for moving said body portionwithin the cavity formed around the tissue to be evulsed, and wherein atleast either of two end portions of said body portion is tapered.
 7. Asystem for evulsing subcutaneous tissue according to claim 2,wherein:said expansion unit comprises an elongated tubular member havingan insertion hole through which said endoscope can be inserted, and anobservation portion which is formed at least in a portion of saidtubular member and which permits observation with said endoscope, andwherein the leading end portion of said tubular member has acircumferential length which is longer than the circumferential lengthof a maximum-diameter portion of said dissector to be inserted into thecavity.
 8. A system for evulsing subcutaneous tissue according to claim3, wherein said dissecting unit further comprises:a leading end portionformed at the leading end of said tubular portion and said observationportion is formed at said leading end for enabling observation with saidendoscope to be performed, and wherein said leading end portion has anouter diameter which is larger than the outer diameter of said tubularportion.
 9. A system for evulsing subcutaneous tissue according to claim1, wherein:said cavity maintaining unit comprises a body portion whichis forcibly brought into contact with tissue surrounding the tissue tobe evulsed and which includes the treatment space formed therein, andsaid body portion has at least one opening through which at least onetreatment tool can be introduced into said treatment space.
 10. A systemfor evulsing subcutaneous tissue according to claim 1, wherein:saidcavity maintaining unit comprises a body portion which is forciblybrought into contact with tissue surrounding the tissue to be evulsedand which includes the treatment space formed therein, and said bodyportion has at least one opening through which said endoscope and saidtreatment tool can be simultaneously introduced into said treatmentspace.
 11. A system for evulsing subcutaneous tissue according to claim1, wherein said cavity maintaining unit comprises:a first tissuedisplacing unit capable of forcibly displacing tissue surrounding thetissue to be evulsed toward the tissue to be evulsed, and a secondtissue displacing unit which movably guides said first tissue displacingunit and which forcibly displaces the tissue surrounding the tissue tobe evulsed into a direction opposite to the direction of displacementperformed by said first tissue displacing unit.
 12. A system forevulsing subcutaneous tissue according to claim 1, wherein said at leastone treatment tool comprises:two shafts capable of relatively moving inan axial direction of said treatment tool, a pair of hooks, each ofwhich is provided for a leading end of each of said shafts and whichproject to side portions of said shafts in the same direction; and anoperation unit which relatively moves said two shafts so as to change adistance between said pair of hooks.
 13. A system for evulsingsubcutaneous tissue, comprising:an endoscope adapted to be inserted intosubcutaneous tissue through a skin cut portion to observe tissue to beevulsed and existing under the skin; a dissecting unit adapted to beinserted into the subcutaneous tissue through said skin cut portion soas to dissect the tissue to be evulsed from surrounding tissue in orderto form a cavity along the tissue to be evulsed and below the skin, thedissecting unit including:a tubular member having an insertion passage,into which said endoscope can be inserted, a distal end portion of thetubular member being formed of transparent material and shaped smoothlysuch that the tissue to be evulsed can be dissected from the surroundingtissue without any damage, and a balloon, formed near the distal endportion of said tubular member, said balloon being capable of beinginflated in a direction of a diameter of said tubular member; a cavitymaintaining unit for maintaining a sufficient space to perform atreatment of the tissue to be evulsed in the cavity formed by thedissecting unit; and at least one treatment tool adapted to be insertedinto the treatment space maintained by said cavity maintaining unit inorder to perform, in the treatment space, treatment required to evulsethe tissue to be evulsed.
 14. A method of evulsing subcutaneous tissue,comprising the steps of:cutting skin at a position near a tissue to beevulsed below the skin to form a cut portion so as to expose part of thetissue to be evulsed through the cut portion; inserting, from the cutportion, a dissector into the subcutaneous tissue along the tissue to beevulsed and forming a cavity below the skin along the tissue to beevulsed while dissecting tissue adjacent to the tissue to be evulsed, bythe dissector; inserting a tunnel-shaped cavity maintaining tool fromsaid cut portion into the cavity formed by said dissector and retainingsaid cavity maintaining tool in the cavity without any external meansconnected thereto to support said tunnel-shaped cavity maintaining tool,so as to maintain a treatment space near the tissue to be evulsed inwhich the tissue to be evulsed can be evulsed; and introducing anendoscope and a treatment tool into said treatment space maintained onlyby said cavity maintaining tool in said cavity so as to separate thetissue to be evulsed from the surrounding tissue by said treatment toolunder observation of said endoscope so as to evulse the tissue to beevulsed to the outside of the body.